Watch terminology

Alarm	A function of the watch which gives a warning in the form of vibration, beep or chime. The word comes from the Middle English alarme which meant call men to arms. In the ancient castles a heavy bell was sounded to awaken the guards in times of danger. In early candle watches, hours were announced by the fall of the nail inserted into the wax, on to a metal gong, at the hour mark. In early mechanical watches alarm feature was somewhat rare. In fact small wound up bedside alarm clock appeared in the 19^th century only. A patent was given to Seth Thomas (American) in 1876 for the idea of the alarm clock.
Altimeter	An instrument for measuring the altitude or height of an object from a fixed level. The word is a portmanteau word (word formed by blending two sounds and two meanings) made using the alti ofaltitude and meter. The instrument was invented by Louis Paul Cailetet (1832-1913), a French physicist. An altimeter fitted watch certainly is a great boon for high altitude sport and flying.
AM and PM Indicator	Method of showing whether the time is AM or PM. This is usually found in watches with GMT or Dual Time Display or World Time Display which helps the viewer to ascertain whether it is day or night in the other time zones. AM is the abbreviation of the Latin ante meridiem (before noon) and PM post meridiem (after noon). Meridiem is Latin for mid-day.
Analog/ Digital Display	A watch that indicates time by hour and minute hands as well by digital display (display of time either by numbers or letters). In analog display it is possible to see the slightest changes in time while in digital display the display of time jumps from one fraction to another. This is also called Dual Display. Digital Display of time in mechanical watches is rare. However, it is very common in electronic watches. Digital display was first exhibited in St.Louis World Fair in 1904, produced by Ansonia Clock Company. In 1903 Eugene Fitch of New York received patent for this clock.
Analogue	A spelling variant for Analog
Annual Calendar	A watch which shows the hour, day, date and month for one year only. In this watch the months with 30 days and 31 days are automatically adjusted. However, manual correction is needed for the first of March to account for the leap year (February could have either 28 days or 29 days). The term is better understood in contrast to the perpetual calendar which needs no manual setting every year till the 2100. Patek Philippe was the first to patent an annual watch calendar in 1996. The system of showing annual calendar went on improving and today many watches feature this.
Aperture	A small opening usually round or squire on the dial of watch to indicate either day or date or both.
Auto Repeat Countdown	In this countdown timer the after the preset time is over the, it resets automatically and goes on repeating until the function is disabled.

Automatic Winding Movement	An Automatic Winding Movement uses a rotor which winds a spring from the movement of the wearer. This wound spring releases power for the movement. The watch should be worn for a reasonable period of time for the movement to work. Abraham Louis Perrelet (1729-1826), a Swiss horologist invented this mechanism in 1770. His movement required the wearer to walk. Fifteen minutes of walk could wind the movement to its full and the watch could work for a week.
Balance Spring	A balance spring also called hairspring is a component of mechanical movements. It is attached to the balance wheel and controls the speed at which the wheels rotate which helps in showing accurate time. This device appeared in movements around 1657. Robert Hooke (1635 – 1703, English Architect) and Christian Huygens (1629-1695, Dutch Mathematician) independently developed this system. Balance greatly increased accuracy of the clocks. Earlier the clocks showed hours of variation. The introduction of the balance spring reduced variation in time to 10 minutes. Subsequently more improvements were made greatly enhancing the accuracy of time keeping.
Balance Wheel	Balance wheel is the part of the movement that rotates back and forth which in turn allows the gears to move a fixed distance which reflects in the hands of the watch. It was not accurate when invented. However, it is known that by about 1500 balance wheels were an essential element watches till the latter part of the 20^th century when quartz movements came to be used in watches.
Barrel	The barrel is closed metal cylinder with gear around it. The main spring, which gives power to the watch, coils on it. The barrel turns on an axle called arbor. The spring is hooked to the barrel at the outer end and the inner end is hooked to the arbor. The gear teeth engage the first pinion among the wheel train. The barrel rotates very slowly, usually one rotation takes 8 hours.
Bezel	A bezel is the circle at the circumference of a watch. Usually it is fixed on the fringe of crystal. In rare cases they are also beneath the crystal. Bezel’s function is to calculate time by using the markers on it in relation to the movement of the hands. Some bezels are unidirectional (turning only in one way) while some are bi-directional, turning in different directions. Many Bezels also are fixed. Some Bezels serves as Tachymeter which is very handy in racing. The word is related to the method of fixing a gemstone or a watch crystal into a metal groove. This is the earliest method of setting stones into jewelry. The rotateable rim later came to be called bezels. The bezel was turned inward and, contained within the bezel, glittered the blue diamond.( “The Blonde Lady” by Maurice Leblanc
Bi-Directional Rotating Bezel	A bezel that can be turned clockwise and anti clockwise.
Bracelet	A bracelet is a metal band that goes around the wrist. The watch bracelets are made of links that afford flexibility. The length of the bracelet can be adjusted to suite the size of the wrist of the user of the watch. The word bracelet is derived from the French word bracel which in turn originated from the Latin word brachialewhich meant belonging to the arm. Bracelet is the diminutive version of bracel. In other words a bracelet is a trinket (something small) belonging to the hand.
Breguet Spring	Inside the balance wheel, a tiny wheel that turns back and forth, is a small hairspring tightly coiled which controls the speed and the back and forth distance of the balance wheel. The precision of the balance wheel is maintained by the balance spring. In 1795 Louis Breguet made an innovation and a spring which applies this came to be called as Breguet Spring or Breguet Coil. He raised up the last coil of the spring and gave it a smaller curve which leads to greater precision.
Bridge	Bridge is the frame on which the watch movement is mounted which in turn is fixed to the main plate of the watch.
Calendar	It stands for the function of a watch which shows the month, and sometimes the day of the week and the year.
Cambered	Slightly arched design of the front cover of the watch is called cambered. Egg: The cambered sapphire crystal.
Caliber/Calibre	Caliber means the particular machine of the watch or clock. It is also called movement. Originally it referred to the size of the movement. Now it is used to refer to specific model of the movement used for a clock or a watch. Each brand has their own system of arriving at the caliber of the movement. Hence, caliber is not a universally accepted system of calculating the power of the movement.
Case	The box in which the watch is housed is called the case. The case could be any metal; the commonest being stainless steel. Other metals like titanium, platinum, god and silver are used in high-end luxury watches.
Chronograph	A watch which can function as a stopwatch. Along with showing normal time the chronograph can show the elapsed time. It has buttons to start, to stop and to reset. Usually the two sub-dials show the elapsed hour and minute. The chronograph function of the watch is driven by the movement of the watch. The word chronograph is combination of the Greek word chronos and graph which means time and writing. The first chronograph was made by Nicolas Rieussec to please King Louis in XVIII in 1821. The king was a die-hard lover of horse race and wanted to calculate the time taken for each race. This eagerness to please the whim of the king resulted in the modern handy tool, chronograph.
Chronometer	It is a precision watch which has received the prestigious certification called COSC (Controle Officiel Suisse des Chronometeres). The certification is given after some grueling tests. The watches are test for 15 consecutive days at three different temperatures and five different positions. Mechanical movements which are precise to -4/+6 seconds are awarded this certificate. Quartz movements do not have much influence by position and temperature. They should be accurate to +/-0.2 seconds per day. Many brands do not go for certification for their quartz movements because of the cost involved.
Complication	An add on function other than time keeping is called a complication. The more popular complications are chronograph, alarm, annual calendar and GMT. Some watches have a grand complication which would include functions like perpetual calendar, tourbillon, minute repeater etc. A watch with any added on function is called a complicated watch.
COSC	This is an acronym of Controlle Officiel Suisse des Chronometres. This is the official authority in Switzerland for testing and certifying watches. See Chronometer.
Countdown Timer	This is a provision in preset timer which helps the user to find out how much of the time has elapsed. Some watches give a warning signal a few seconds before reaching the pre set time.
Crown	This is an ergonomically designed grooved round object outside the case of a watch used for winding the main spring, setting the hands of the watch and for setting day and date etc. The crown is also called the winder or the wining stem.
Crystal	It is the lucid cover on the watch face (dial). Various materials like glass, plastic, mineral crystal or sapphire crystal, a scratch-resistant artificial material are used. It is a protective lid for the watch which also gives proper visibility at the same time.
Day/Date	A watch which shows both the day of the week and the date of the month along with time. They can be called also a Calendar Watch. The display of hour and minute was the bare essentials of the watch from the early days of horology. Soon seconds were shown followed by date and the day of the week as well. There are two modes of display, analog and digital. However, most watches show time in analog mode and date and day through either a square or round slit.
Day/Night or AM/PM indicator	Go to AM/PM Indicator
Deployment (Deployant) Buckle	It is a buckle that is attached to both ends of the strap. The buckle can be unfolded making it easy to put on the wrist or take out of the wrist. Once the watch is around the wrist this buckle can be folded. This makes wearing the watch easier and protects the watch from falling down while wearing. This reduces the wear and tear of the strap. Buckles are one of the most widely used trinkets in the world and hence taken for granted. In fact it is one of the most reliable devices for fastening a range of things. The word is derived from the Latin word buccula which meant cheek strap. The word is military in origin. It was used on the helmets of Roman soldiers. Buckles were prominently used by the Roman soldiers on their body armor too. Originally the buckles were made of bronze and were ornamented to embellish the looks of the soldier.
Digital Display	Watches which show time in number or digits in contrast to those which show time by hands on the dial. Now LCD, Liquid Crystal Display is commonly used. The first digital mechanical pocket watches appeared in late 19^th century. In 1920 digital mechanical wrist watches appeared. The first digital wrist watch saw the light of the day in 1972 made by the American timepiece maker, Hamilton Watch Company.
Dual Time	This is a display of local time along with the display of time from another time zone. This is done by using an additional hand or a sundial. In 1853 Tissot made the first dual time zone watch.
Duo Display	This is a display in analogue (hour and minute shown on the dial by hands) as well as digitally (display in numbers). Another word for this display is AnaDigi, a portmanteau word derived by joining together the first syllables of Analogue and Digital.
Dial	It is the watch face time and other functions are displayed.
Elapsed Time Rotating Bezel	A bezel with marking on it that can be turned. It is used to track periods of time. By turning the Bezel the user can align the zero on it with the minutes or seconds hand. Merely looking at the bezel the user can find out the elapsed time. This saves him the trouble of calculating time with out having to do the subtraction.
Engine Turning/Turned	This is also called guilloche. This is age old skill which even today employs antique tools to etch fine patterns on the various parts of the watch like cases, dials, bezels etc. The equipments used for engine turning are no longer in production, and are difficult to make. They are very intricate, bulky pieces of engineering yet need no electricity and are completely manually operated. There are two types: the straight line engine, for engraving straight lines at any angle, and the rose engine, which etches in circles. Pattern bars can be used to etch undulating lines, instead of a basic straight (or round) cut, and by offsetting this pattern each time, and adjusting the cutter position, an endless number of dissimilar patterns are feasible.
Equation of Time or EDT	There is a difference between solar time and our time. Solar time is the true time and our time is the mean solar time. Since the movement of the earth is in an elliptical pattern and its axis is slightly tilted there are only 4 days in a year when the night and day is exactly of the same duration. These days are April 15^th, June 14^th, September 1st and December 24^th. On all other days the days are either short or long depending on the position of the earth. An Equation of Time or EOT is a complication that indicates the between the true time and the mean time.
Escapement	The device in the center of practically all the mechanisms of time keeping. It provides the impulses to maintain the oscillations of the wheel or the pendulum which governs the rate to which escapement allows the wheels and the hands of the watch to turn.
Fly-back Chronograph	Retour-en-vol is French which means a chronograph which starts again the moment it is brought back to zero without having to stop, reset & restart the chronograph – it is principally helpful to pilots. Pressing the lower push-piece only, they can instantaneously reset the chronograph to time each following leg of a search pattern. Without this skill they would have to use two push pieces to stop, return to zero and restart the chronograph while beginning a new leg. The fly-back function came out in 1923 and was developed by Breitling. However, the patent of the fly-back chronograph goes to Longines with its first fly-back chronograph dating back to 1936.
Function	A word applied to explain the range of different tasks a watch can carry out such as chronograph and countdown timer. These are also called complications.
Gear Train	The arrangement of gears which pass on power from the mainspring of the watch to the escapement.
GMT Time Zone	Greenwich Mean Time (GMT) is some times also called as Zulu Time and UTC (Universal Time Coordinated). In 1884, the International Meridian Conference at Washington DC, USA, it was approved as the standard by which all World Time is organized. It placed Greenwich on the Prime Meridian (Zero Longitude). Greenwich Mean Time or GMT is the referral standard for all other time zones in the world. It is the identical all year round and is not affected by Summer Time or Daylight Savings Time. GMT was originally set-up to help marine navigation when the globe started to open up with the finding of the “New World” (America) in the fifteenth Century. In general when the GMT term is used with watches it refers to the capability of the watch that shows local time and the time in at least one other time zone in a 24 hour mode. The reason for showing the other time zone in 24 hour mode is to let the wearer to know if the second time zone is in AM or PM. See Dual Time, World Time.
Gold Plating	A coating of gold that is plated onto a common metal case or bracelet to improve its appearance. The thickness of the plating is measured in microns (1000th of a mm).
Guilloche	This is also called engine turning. This is also called guilloche. This is age old skill which even today employs antique tools to etch fine patterns on the various parts of the watch like cases, dials, bezels etc. It is called guilloche in French after the French engineer “Guillot”, who invented a machine that could etch fine patterns and designs on metallic surfaces. Refer: Engine Turning
Hairspring	A very thin spring in a mechanical watch that produce the recoil of the balance wheel. The length and adjustment of its length control the watch’s regularity. It is also called a balance spring. There is some disagreement as to whether it was invented around 1660 by British physicist Robert Hooke or Dutch scientist Christian Huygens. Most probably Hooke first had the idea, but Huygens built the first working watch that used a balance spring.
Helium Escape Valve	Professional Divers watches are made taking into consideration the needs of a professional diver. These divers repeatedly spend extensive periods of time in diving bells at pressure, breathing Hypoxic trimix or other mixed gases with helium in them. Since helium is such a tiny molecule over time in a pressurized diving bell, helium will sneak its way past a dive watch. While at depth this causes no problem, it will as the divers decompress the helium which is unable to escape the watch. With a standard dive watch this would lead to the watch crystal popping out from inner pressure. To avoid this happening, technically advanced professional diver watches employ a helium escape valve to allow this extra pressure during decompression. Some watch companies solve the issue by providing an extra strong case. Rolex and Doxa S.A. together created the helium escape valve in the 1960s. It was first introduced in the Rolex Submariner/Sea-Dweller and the Doxa Conquistador.
Horology	The discipline of time measurement, encompassing the skill of designing and making of all kinds of devises for this, like clocks and watches. The word is formed by the combination of the Greek word hora (hour) and –logy (knowledge). The word came into English around 1810. Though it is not exactly known when the word came to be used in other languages it is possible to infer that the Romans were the first ones to use this term. The ancient Roman water clock was known as Horologium. Many Latin speaking cultures freely adapted this word to describe their time keeping devises. Many years later in 1656 when Christian Huygens invented the first pendulum clock based on Galileo’s design it was called Horologium Oscillartorium which was later shortened to Horoglogium.
Index Hour Marker	A line design or a plain stick used as an hour indicator on the dial of an analog watch instead if the numerals
Jewels	The synthetic gemstones used by the watch makers in order to reduce friction and wear which act as bearing for the gear train. In 1704 Nicolas Fatio de Duillier, Peter Debaufre and Jacob Debaufre invented jewel bearings. For their unique idea they had been given an English Patent. Originally natural jewels like diamonds, sapphire, ruby and garnet were used. In 1902 a method of making synthetic sapphire and ruby was developed which make jewel bearing affordable and became the universal feature in most mechanical watches. Earlier the jewel bearing were made by tools made of diamond abrasives. Nowadays lasers are employed in the making of the bearings.
Jump Hour/Minutes	Rather than a watch hand continuing to move, a jumping display employs numerals seen through an aperture, which instantaneously change on the hour or minute. The round motion of hands has been taken up by people as the most normal way to express the elapse of time. In nature as seen in the planets the movement is more in circular fashion. Jumping display is another way of displaying time, either the hour or minute. Instead of by the hand time is displayed through an aperture through which the numerals inscribed on a disc are made visible. The shift from one time marker to the other is instantaneous. In some watches jumping minutes are also seen. The more common practice is to equip the jumping hours with retrograde minutes. The first jump hour models were made in the 19^th century as pocket watches. The first one was made by the French watch making company called Blondeau for the French King Louis Phillippe d’Orleans in 1830. Mass production was started when Joseph Pallweber, a Swiss timepiece maker created the mechanical digital clocks in 1956. When the electronic digital watches became popular in 1960s (they were very costly then) as a cheaper alternative to the electronic digital watch. Though Jump hour watches were there in the market quite some time they have not received the universal acceptance which the other types of displays. However, there is a revival of interest in them due to the futuristic designs which some brands have launched in the market.
Lap Timer	A utility in a chronograph watch that lets the user to time laps of a race. At the finish of a lap, the timer is stopped and then returns to zero to start timing the next segment.
Lever Escapement	A lever which is divided into two pallets which one after another stops and releases the escape wheel. This carries out the timing function of the balance wheel. The invention of the lever escapement is made by Thomas Mudge (1715-1794), an outstanding English watch maker who made the invention and applied to clocks. Later it was applied to watches. This is considered one of the greatest innovations on the watches which even today remains the integral part of all mechanical watches. Later Breguet and Massey made improvement on it and perfected it.
Liquid Crystal Display (LCD)	LCD or Liquid Crystal Display shows time in numbers. The display is done by the liquid which is held in a thin transparent tube. There are seven segments for the display. When all are activated we get the number eight. Activation of the display is done by electronic impulse. Liquid crystals were first discovered in 1888 in cholesterol taken from carrots by Austrian botanist and chemist Friedrich Reinitzer. In 1972 the international Liquid Crystal Company owned by James Fergason (1934-2008), an American, produced the first modern LCD watch.
Luminous	Luminous means emitting light. This is now the standard feature in many clocks and watches. The hour and minute markers as well as the hands of the watches are larded with luminous material which emits light. It helps the user to know the time at night. The word came to English in the 15^th century from Latin lumen which means light. Luminescent materials have a long history. The Chinese and the Japanese used luminous material in their painting thousands of years ago. By the end of the 19^th century Swiss watch makers began to use luminova on dials and hands of watches.
Lugs	The projecting brackets at the ends of the watch case which holds in place the strap or the bracelet.
Main Plate	It is the foundation plate upon which all the parts of the movement of the watch are mounted.
Mainspring	A mechanical watch derives its power from a coiled spring which is called the Mainspring.
Manual Wind Movement	A manual wind movement of the watch works by winding the crown by the hand which winds the mainspring in the watch case. Once wound it provides power to the movement for a specified time. Some watches work for a few hours other for days.
Marine Chronometer	Marine Chronometers are used on board ships to determine the longitude. They are highly accurate mechanical or electronic watches which are kept in a box. Since they are often kept boxes they are often called box chronometers. To work accurately they have to maintain a horizontal position. This is achieved by mounting them on gimbals.
Measurement Conversion	It is a feature in the bezel of a watch that allows the user to convert a kind of measurement to another by using the graduated scales that has been etched on it.
Mechanical Movement	A mechanical movement is the power source of a watch that derives energy from a mechanical source. The mechanism of the watch is made up of many parts, gears, screws and springs. By winding the main spring the watch will start working. There are two types of mechanical movements manual and automatic. In the manual type the main spring is manually wound while in automatic the spring is wound by the movement of the rotor by the movement of the user.
Micron	This is a unit that is employed in the plating of the gold. It is a thousandth of a millimeter.
Minute Repeater	This is a watch in which the hours, quarters and minutes are audible. By using the buttons or slides on the case’s edge the feature can be activated or cancelled. The feature was very much in vogue before displays became common to allow people to know the time in the dark. They are also useful for the visually challenged. Today in many watches it is a feature that adds to the novelty of the watch. Repeating clock was first made by the Reverend Edward Barlow in 1676. Making the repeaters was expensive. During the nineteenth century these clocks became somewhat redundant due to the availability of artificial lighting which enabled people to know time even at night.
Mono (Single) Pusher Chronograph	A stop watch that works by using a single button. Majority of the stop watches need two buttons, one to start and stop and another one to reset. A Mono Pusher complication manages to do all the three operations on the same button.
Moonphase	A moon phase watches makes visible the various phases of the moon through a slit. Twenty nine and half days are shown like that. Some watches also do the correction 44 minutes a month.
Mother of Pearl	This is the interior of a freshwater mollusk that is used to embellish the dials of the watches. This is available in different colors like milky white, blue and pink. Mother of Pearl is the medieval translation of the Latin mater perlarum. In this combination the word mother is used in the sense of the first element, a sense that is obsolete today.
Movement	The machine of the watch that keeps time and performs various functions. See Automatic Wind Movement, Manual Wind Movement and Quartz Movement. Instead of the word movement in modern electronic and quartz timepieces often the word module is used instead.
Numerals	The hour, minute and second markers in a watch. Roman and Arabic numerals are used to present information on the dials and on the sub dials.
Perpetual Calendar	The complication which shows date, day, month & leap year cycle. Some will also display moon phase and the year. The complication can automatically adjust for months with 30 days and 31 days as well as 28 days. It can also automatically adjust the leap year. Perpetual Calendar was first created in 1898 by Patek Philippe which was worn on the neck. This became the prototype for all the future perpetual calendars to come. However, the privilege of making one suited for the wrist watch was done by Rolex after 30 years. This is called Rolex Reference 8171. Subsequently IWC came out with single crown perpetual calendar displaying all the four digits of the year. This was in 1985.
Platinum	Among the precious metals platinum is the toughest and extremely rare. It does not get dim by use and has sheen as well as glow. Due to these qualities the metal is the choice for many high-end and limited edition watches. Its name is derived from the Spanish term platina, which is literally translated into “little silver”. It was initially used by pre-Columbian South American natives to make works of art. It was referenced in European writings as early as 16^th century, but it was not until Antonio de Ulloa (12 January 1716 – 3 July 1795) brought out a report on a new metal of Colombian origin in 1748 that it came to be studied by scientists.
Power Reserve Indicator	Power reserve indicator shows the present level of energy that is available to the movement in a winding watch. A hand shows the number of hours the movement will work before it comes to a halt. Another word for the same is Reserve de Marche.
Pulsimeter	This devise helps in measuring the pulse rate in a chronograph.
Push-Piece	It is a button or a pusher which when pressed starts or stops a function in a chronograph, alarm or date indicator.
Quartz Crystal	Quartz is a piezoelectric substance with piezoelectric qualities which means that it produces an electrical charge when mechanical force is applied. This also pulsates when an electrical energy from an exterior source, such as a battery, is applied. Pierre Curie and his brother Jacques discovered piezoelectricity way back in 1880. However, it practical application saw the light of day only in the early 1920’s. W.G. Cady understood that due to their flexible qualities, mechanical strength and durability quartz crystals could be used to produce very stable resonators. By various experiments he found out that the crystal could be cut in special ways so as to make resonators of virtually of any frequency that functioned smoothly in all temperature conditions. The credit of using Quartz crystals for measuring time goes to Warren Marrison, who invented the first quartz clock in 1927. Mass production of quartz crystals for watches was made possible by the efforts of Juergen Staudte in the first part of the 1970. This made watches an affordable gadget for any person.
Quartz Movement	It is a movement which derives its power by employing the quartz technology. In this technology the introduction of electricity triggers oscillation in a quartz crystal. The power for setting in motion the quartz is derived from battery. The quartz movements are generally more accurate that the mechanical movements and far cheaper and easier to produce.
Rattrapante Aka Split Seconds Chronograph	This Chronograph can measure the laps of events that start at the same time. It has two hands that can run at the same time with main chronograph hands. But it can be stopped while the chronograph continues its movements.
Stainless Steel	As evident from the name it is a metal alloy that does not rust, corrodes and discolors. Due to this it is highly suitable for the case and the bracelets of the watches. Watches made of other metals often can have there backs made of this alloy. In metallurgy, stainless steel, also branded as inox steel or inox from French “inoxydable“, is a steel alloy with a smallest amount of 10.5% to 11% chromium content by mass. The corrosion resistance of iron-chromium alloys was initially documented in 1821 by French metallurgist Pierre Berthier, who understood their resistance against attack by some acids and suggested their application in cutlery.
Stopwatch	Ref. Chronograph.
Stepping Motor	The component in the quartz analogue movement that sets in motion the gear train and thus sets in motion the watch hands.
Sterling Silver	It is a precious metal which has a high degree of ability to reflect light. It has a rare quality of luster in it as a result often used in the making of watches and watch dials. It is 92.5% pure. Sterling silver is an alloy of silver having 92.5% by mass of silver and 7.5% by mass of other metals, usually copper. The word in origin refers to the newly introduced Norman silver penny in England in the 12 century. According to the Oxford English Dictionary, the most reasonable etymology is root from a late Old English steorling(with (or like) a “little star”), as some early Norman pennies were stamped with a small star. There are a number of outdated hypotheses. One proposes a link with starling, because four birds (martlets) were shown on a penny of Edward I, and a different, a hypothetical association with Sterling silver, a word for inhabitants of the Baltic, or the Hanse, towns of eastern Germany. This etymology is itself medieval, suggested by Walter de Pinchebek (ca. 1300) with the details that the coin was at first made by moneyers from that area.
Subsidiary Dial	It is small sub-dial on the face of the watch in order to show additional functions like date, power reserve and elapsed tome.
Swiss-Made	Swiss-Made claim of a watch requires that the assembly work of the movement as well as of the watch were commenced in and was managed by a manufacturer in Switzerland. In addition 50% of the components of the watch should have been made in Switzerland. The components brought from outside should arrive in unassembled condition. The entire quality control should be based on Swiss standards and it is monitored by legally constituted Swiss authority. The stringent legal conditions imposed on the use of Swiss or Swiss Made have helped the Swiss to enjoy a solid global reputation. Globalization has not diminished this reputation. The Swiss are not the only watchmakers in the world. Inspite of stiff competition from many quality conscious countries the reputation of the Swiss remains untarnished. Even the prestigious brands that have global reputation have not given up the Swiss Made label. The reputation is maintained by the Swiss authorities by waging continuous battle with counterfeit watch makers. For this they make use of the existing laws of each country and also by signing bilateral agreements with other countries. In brief the Swiss maintain a constant vigil to live up to the reputation. The Swiss enacted a law in 1993 to secure adherence to the stringent quality control regime of the country and the customs closely watch both the import and export of the goods. Some places in Switzerland also enjoy brand equity like Geneve. Counterfeiters whose imagination is creative now use these names instead of Swiss. There are stringent rules for using the Swiss label. For example if the movement alone is Swiss Made it has to be indicated by writing Swiss made movement. If the bracelet alone is Swiss made. It has to be made clear by writingSwiss Made Bracelet.
Swiss A.O.S.C.	It is the abbreviation for Appellation d’Origine Suisse Certifiee – Swiss Certified Label of Origin. This mark is the identification for the watch and its components are of Swiss origin.
Tachymeter Scale aka Tachometer	This is a feature in Chronograph watches. It calculates the speed at a pre determined time. The user starts the Chronograph in the beginning as well at the finish. The user can read the speed of the vehicle per hour by viewing a scale which is engraved on the bezel of the watch.
Tang Buckle	Tang buckles consist of buckles with a metal look and a pin. This is fixed on one end of the strap. The other end has a number of holes. The pin and holes are fastened together to keep the watch properly on the wrist. The word tang originally meant a serpent’s tongue which is an organ for stinging. By 1680s the word came to be used for any sharp extension of a metal blade or any pointed metal tool.
Tank Watch	Tank watch is the name of design inspired by the tracks of tanks used in the World War II. It is a rectangular watch with two lines on its face. Inspired by the Tank Louis Cartier designed it. The etymology of the word Tank is a matter of scholarly study. The word tank is applied to many Cartier watches. Though many people say that it stands for the military hardware called tank others wonder how such a gentle thing like a watch could be given such a name. Some say that the shape of the watch gave rise to the name; others the tank treads gave the suggestion of the name. There are others who feel that this is the French way of honoring the American tanks which secured the victory in the World War 1. In fact it remains a fascinating little mystery as there are Cartier Tank Americaine, Cartier Tank Francaise and Cartier Tank Anglaise.
Timer	A tool for showing intervals of time with out showing the time of day.
Titanium	It is a rare and costly metal, a little darker in hue than stainless steel. It is lighter than steel at the same time stronger than steel. It does not corrode even in salt water. Due to its strength and the corrosion resistant qualities it is used by many high-end watch makers especially for their divers and sports watches. The word originates from the Greek word Titanos, which means Titans who according to the Greek mythology were the first sons of the earth. German chemist Martin Heinrich Klaproth (1743-1817) named it. He had named previously another element Uranium which was the other son of the earth.
Totaliser	It is a method of tracking and showing elapsed time. It is usually done on a subdial
Tourbillon	When watches are held in different positions it affects the accuracy of the watch movement. In order to counteract this, the balance and escapement are mounted in a rotating cage. Due to the rotation of the cage the watch passes through all the possible positions which average out the errors. Tourbillon platforms usually rotate every minute; in some case the rotation is in every 4 or 6 minutes. Tourbillon technology requires great precision and hence employed only in the making of premium watches. The term tourbillon is French in origin which means whirlwind. The technology was developed in early 1795 by the French-Swiss watch maker Abraham-Louis Breguet working on an earlier idea of English Chronometer maker named John Arnold.
Uni-Directional Rotating Bezel	It is a bezel of the watch that can be rotated only in one direction to calculate the elapsed time. There is a special lock that prevents the bezel from turning in the other direction. The turning the bezel in the other direction will involve in the wrong calculation of the elapsed time. In hazardous operations like diving, an error can endanger the life of the driver. The diver has to accurately calculate the time in order to ascertain the quantity of air that is available. His time of stay in the under water is decided by accurate calculations.
Vibration Per Hour or VPH	The movement of the oscillating element is limited by two extreme positions. The movement of the balance is with in this limit. The balance vibrates at the rate of five or six times in a second. These vibrations per second are rendered as vibration per hour (VPH). So VPH could be 18,000 or 21600.
Water Resistance	Water Resistance is the capacity of watch to resist the entry of water into the watch case. All watches have some degree of water resistance. The watch manuals that accompany the watch usually explain the level of resistance a watch has. The watch resistance indicated in watches is determined under test conditions. This resistance will decline by the aging and wear and tear of the watch. The seals and gasket also may not function after a few years. In diving and aquatic sport watch resistance is crucial and companies make watches for this niche area with high degree of water resistance.
Winding	Winding is the method of tightening the mainspring of a watch. In manual mechanic watch it is done by turning the crown which tightens the main spring. Depending on the power reserve of the watch the winding has to be done at specified intervals. In automatic watches the winding is done by the movement of the user. The movement of the user of watch sets in motion a rotor which in turn tightens the mainspring. Just as the manual winding watches need periodic winding the automatic watches need some movement of the user to set in motion the rotor. Prolonged idling of the watch might stop the watch.
Winding Stem aka Winding Crown	Ref: Crown
World Time Complication	A watch that shows the time of 24 time zones around the world is called World Timers and this complication is called World Time Complication. The names of the cities are printed on the dial and looking at the direction of the hour hand the hour can be read.