alarm: A beeping sound that notifies users of a pre-set time.
altimeter: A device that determines altitude based on changes in barometric pressure. An altimeter is often integrated into outdoor sport watches such as several models manufactured by Suunto Watches.
analog: A watch that uses hour and minute hands to show the time.
analog-digital display: A watch that uses analog (hour and minute hands) as well as digital (numbers) to show the time.
anti-magnetic: A watch that is not susceptible to magnetism, which is often found in televisions, speakers, refrigerators, and other electronics. Electronic watches are anti-magnetic; whereas, mechanical watches can be thrown off balance if they come in contact with a strong magnetic field.
automatic watch: A mechanical watch that is wound by the movements of the wearer's arm. Although quartz watches are more common, automatic watches are available from a number of manufacturers including Swiss Army.
automatic winding (or self winding): A watch with a mechanical movement that is wound by the motion of the wearer's arm, not by turning the winding stem. If it's not worn for a couple days, an automatic watch will need to be wound by hand to get it started again.
balance: On a mechanical watch, an oscillator regulates the speed of the movement.
balance spring (hair spring): On a mechanical watch, a very fine spring that returns the balance wheel to a neutral position.
balance wheel: On a mechanical watch, the part that oscillates, dividing time into equal segments.
battery reserve indicator (end-of-battery indicator): A feature on some battery-operated watches, this indicates when the battery is near the end of its life often by the second hand moving in two-second intervals.
bezel: The ring that surrounds the watch dial, or face. It's usually made of gold, gold plate or stainless steel.
bi-directional rotating bezel: A bezel that can be rotated either clockwise or counterclockwise, to be used for mathematical calculations, such as average speed, average distance, or elapsed time.
bracelet: A watch band made of links.
built-in illumination: A light on a watch that lets the wearer read it in the dark.
cabochon: A decorative stone that has been carved into a round shape.
calendar: A feature that shows the date. On some watches, it also shows the day of the week.
caliber: A term used to indicate the movement's shape, layout, or size.
cambered: Refers to a curved or arched dial or bezel.
case: The metal housing of a watch's parts.
caseback: The back side of a watch case (the side that lies against the skin).
case materials: The materials used in a watch case. Can be inexpensive cast metal or a solid metal, such as steel, gold, platinum, or titanium. Some watch cases have gold plating over brass.
chapter ring: The ring of figures and minute marks on the watch dial. The hour marks are sometimes called chapters.
chronograph: A watch with a built-in stopwatch function. The accuracy of the stopwatch can vary from 1/5th second to 1/100th second.
chronometer: A label given to Swiss-made watches that meet very high standards set by the Swiss Official Chronometer Control (COSC).
complications: Features added to a watch beyond basic timekeeping. These can include perpetual calendars, moonphase displays, alarms, repeating mechanisms, chronograph functions, power reserve indicators, and tourbillons.
cosmograph: Similar to a chronograph but with the tachymeter on the bezel instead of on the outer rim of the dial.
countdown timer: A function that keeps track of how much of a pre-set period of time has elapsed. May include a warning signal just before time runs out.
crown(stem) (pin): The button on the outside of the watch case used to set the time and date. In a mechanical watch the crown also winds the mainspring. If the crown screws into the case (called a screw-in or screw-down crown), it makes the watch watertight.
crystal: The transparent cover on a watch face made of glass crystal, synthetic sapphire or plastic. High-quality watches typically have a sapphire crystal, which is highly resistant to scratching or breaking.
day/date watch: A watch that indicates both the date and the day of the week.
day/night indicator: A colored or shaded band on a watch showing world time that indicates which time zones are in daylight and which in darkness.
deployment buckle: A buckle that pops open and fastens using hinged, often adjustable, extenders.
depth alarm: An alarm on a diver's watch that sounds when the wearer exceeds a pre-set depth.
depth sensor/depth meter: A device on a diver's watch that determines the wearer's depth based on water pressure.
dial: The watch face.
digital watch: A watch that shows the time through digits instead of a dial and hands. While digital watches fell out of favor following an initial wave of popularity after they were introduced in the 1970s and 1980s, they have fashionable once again with brands such as Nooka
direct-drive: A function that allows the second-hand to advance in intervals instead of a smooth sweep, allowing for more precise timekeeping.
dive watch: Dive watches are watches which have a minimum 200 meters of water resistance. In addition, they often have an elapsed time bezel, highly visible hands and markers and are constructed of materials that resist corrosive salt water.
dual timer: A watch that measures current local time as well as at least one other time zone.
Eco-Drive Technology: Solar power technology employed by Citizen Watches in most of its quartz models.
E Ink: Technology used in the display of Phosphor Watches which replicates the appearance of paper and ink. Also called Electronic Paper Display, or EDP, the technology is based on small capsules, about the diameter of a human hair filled with an equal number of negatively charged black particles and positively charged white particles floating in a clear liquid medium. The capsules are arranged in a thin sheet and laid over electronic circuitry which can form patterns of pixels. The patterns of pixel cause the black and white particles in each capsule to gravitate either to the top or the bottom of the capsule. What the the viewer sees on the watch's dial is an actual fluid ink display that can change instantly. But all you really need to know is it looks really cool..
elapsed-time rotating bezel: A graduated rotating bezel that keeps track of elapsed time. Turn the bezel to align the zero with the watch's seconds or minutes hand, and then check it to see how much time has passed (without needing to subtract).
electronic (quartz) watch: A watch that uses an electric current. While most are battery powered, some use solar cells to transform light into electrical energy.
face: The visible side of the watch.
flyback hand: A seconds hand on a chronograph that can be used to time laps or to determine finishing times for several competitors in a race.
gasket: Seals the case back, crystal, and crown to protect against water infiltration during normal wear. The gaskets should be checked every two years to maintain the watch's water resistance.
gold plated: A base of metal covered with a layer of electroplated gold.
grande complications: Describes a mechanical watch with an abundance of complications.
guilloche: A style of intricate engraving popular on watch dials.
hard metal: A scratch-resistant metal created by binding titanium, tungsten carbide, and other materials and then pressing them into an extremely hard metal. A polish of diamond powder is used to add brilliance.
index: An mark that indicates hours on an analog watch face (instead of numbers).
integrated bracelet: A watch bracelet that is incorporated into the design of the case.
jewels: Synthetic sapphires or rubies that act as bearings for gears in a mechanical watch to reduce friction, making the watch more accurate and longer lasting.
Kinetic: In certain Seiko models, this refers to a technology that uses quartz movement without a battery. Instead, the watch is powered by the movement of the wearer's wrist and can store power.
lap timer: A chronograph function designed to time segments of a race. The timer is stopped after each lap, and it returns to zero to begin timing the subsequent lap.
limited editions: A style manufactured in a specific amount, often numbered, and available in limited quantities.
liquid-crystal display (LCD): A digital watch that uses a liquid held in a thin layer between two transparent plates to display the time electronically. Many computer monitors and televisions also use LCD.
lugs: Projections on a watch face that attach the watch band or bracelet.
luminescence: The emission of light produced by bioluminescence, fluorescence, phosphorescence, or other methods. On watches, some manufacturers use varying techniques to make the dial hands or other parts give off a low light.
main plate: Base plate to which the entire watch movement is mounted.
mainspring: The driving spring of a watch.
manual wind: A watch that must be wound every day.
measurement conversion: A feature that lets the wearer translate one type of measurement into another, such as miles to kilometers.
mechanical movement: A movement powered by a mainspring working in conjunction with a balance wheel.
micron: Unit that measures the thickness of gold coating. 1 micron = 1/1000mm.
military time (24-hour time): Time measured in 24-hour segments; to convert 24-hour time to 12-hour time, simply subtract 12 from any number 13 or larger.
moonphase display: A feature that displays the phase of the moon.
mother-of-pearl: The hard, pearly, iridescent substance found on the inner layer of a mollusk shell. Most commonly a milky white, mother-of-pearl is also found in silvery gray, gray blue, pink and salmon.
movement: The inner mechanism of a watch that keeps time and moves the watch's hands and calendar.
multi-functional: Describes a quartz watch with extra features.
perpetual calendar: A calendar that automatically adjusts for the months' varying lengths and for leap year.
platinum: One of the strongest and heaviest, as well as rarest, precious metals. Platinum is hypoallergenic and tarnish resistant.
power reserve: Energy stored to keep a watch running; the power reserve indicator shows how much power remains.
power reserve indicator: Shows when the watch will need a new battery or winding in the near future.
pulsimeter: A scale on a chronograph watch for measuring the pulse rate.
pushers (push pieces): Buttons on chronographs and some other complicated watches used to start and stop a stopwatch. Can also be used for other functions.
physical vapor deposition (PVD): A gold-colored finish created with a coating of titanium nitrate covered by a coating of 22k gold.
quartz crystal: A tiny piece of synthetic quartz that oscillates 32.768 times a second, dividing time into equal segments.
quartz movement: A movement powered by a quartz crystal. Quartz movement is highly accurate and less expensive to produce than mechanical movement.
repeater: Chimes the time when a button is pushed.
rose (or pink) gold: A soft-hued gold with a higher concentration of copper in the alloy than yellow gold.
rotating bezel: A bezel that can be turned to perform timekeeping or mathematical functions.
rotor: The part of an automatic mechanical watch that winds the movement's mainspring.
sapphire crystal: A crystal made of synthetic sapphire, which is transparent, shatter-resistant, and scratch-resistant.
screw-lock crown (screw-in crown) (screw-down crown): A crown that can be screwed into the case to make the watch watertight.
second time-zone indicator: A second dial on a watch, so the wearer can keep track of local time and time in a second time zone simultaneously.
self winding (automatic winding): A watch with a mechanical movement that is wound by the motion of the wearer's arm, not by turning the winding stem. If it's not worn for a couple days, an automatic watch will need to be wound by hand to get it started again.
shock resistance: A watch's ability to withstand an impact equal to that of being dropped onto a wood floor from a height of 3 feet (as defined by U.S. government regulation).
skeleton case: A case with a transparent front or back, so the watch's movement can be seen.
solar compass: A compass that uses a rotating bezel to determine the geographical poles.
solar powered: A watch that uses solar energy to power the quartz movement. It actually uses light from any source, not just the sun.
split seconds hand: Two watch hands: a flyback and a regular chronograph hand. When the chronograph is in use, both hands move together. To time laps or different finishing times, stop the flyback hand and the regular chronograph hand will keep moving, thereby splitting the hands.
spring bars (or pins): Spring-loaded bars used to attach a strap or metal bracelet to a watch case.
stainless steel: An extremely durable metal alloy virtually immune to rust, discoloration and corrosion. Often used on watch casebacks, stainless steel is also a popular setting for diamonds.
stopwatch: A watch that measures intervals of time. When a standard watch has a stopwatch feature, that entire watch is called a chronograph.
sub-dial: A small dial on a watch face used for keeping track of elapsed minutes or hours on a chronograph. The dial can indicate the date or another feature.
Swiss made: A watch that is cased in Switzerland, contains a movement of Swiss origin, contains at least 50% Swiss parts, and passes its final inspection.
Swiss A.O.S.C. (certificate of origin): A mark identifying a watch that has been assembled in Switzerland containing components of Swiss origin.
sweep seconds hand: Seconds hand mounted in the center of the watch dial.
tachymeter(tachometer): Measures the speed the wearer has traveled over a distance.
telemeter: Determines the distance of an object from the person wearing the telemeter by measuring how long it takes sound to travel that distance.
30-minute recorder (or register): A sub-dial on a chronograph that can time periods of up to 30 minutes.
timer: Registers intervals of time.
titanium: A metal that is much stronger and lighter than stainless steel. Titanium is hypo-allergenic.
tonneau watch: A watch shaped like a barrel, with two convex sides.
totalizer: Keeps track of and displays elapsed time.
tourbillon: A device that mounts the watch's escapement in a small revolving cage to overcome the effects of gravity, allowing for precision in a mechanical watch.
tritium: In tritium illuminations systems, such as those employed in Luminox watches, tritium gas is injected into glass tubes coated with a luminescent paint. The tritium gas excites the luminescent material, which will glow continuously for about 25 years without the need for exposure to light.
two-tone: Two metals combined, such as yellow gold and stainless steel, for a distinct look.
12-hour recorder (register): A subdial on a chronograph that can time periods up to 12 hours.
uni-directional rotating bezel: An elapsed time rotating bezel that moves only counterclockwise. This is common on divers' watches to prevent a diver from has accidentally knocking the bezel off its original position and overestimating his or her remaining air supply.
waterproof: No watch is fully 100 percent waterproof, and using the term waterproof is misleading and illegal.
water resistance: The ability to withstand water. Terms such as 'water resistant to 50 meters' indicate that the watch can be worn underwater to a specific depth.
white gold: With a color similar to silver or platinum, white gold is created by incorporating either nickel or palladium with yellow gold to achieve a white color. Most watches made of white gold are 18k.
winding: Tightening the mainspring of a watch by turning the crown (on an manual watch) or via the rotor (on an automatic watch).
winding stem (crown): The button on the right side of the watch used to wind the mainspring.
world time dial: Usually located on the outer edge of a watch face, this dial tells the time in up to 24 time zones around the world. To use, check the scale located next to a city's name and then add (or subtract) that amount from the local time.
yacht timer: A countdown timer that sounds warning signals during the countdown to a boat race.
yellow gold: The traditional gold color. Yellow gold used in watches is typically 14k or 18k.