EDUCATION - WATCH GLOSSARY
Watch Education

Alphabetical list of Watch Glossary Terms

Accuracy
Refers to rate constancy of a watch, not only on whether it is showing the exact time. A watch that gains or looses exactly the same amount every day is considered accurate.

Acrylic Crystal
Sometimes referred to as Hesolite, an acrylic crystal is composed of a plastic composite that is generally less expensive and less durable than a sapphire or mineral crystal. Acrylic crystal flexes rather than shatters on impact, it produces little glare under bright light, and can be polished easily.

Alarm
A feature that sounds an alarm at a pre-set time or at regular intervals. Alarms are available on both quartz and mechanical watches.

Altimeter
Commonly found on pilot watches, an altimeter provides altitude by responding to changes in barometric pressure.

Analog Watch
Displays the time with a dial, hands, and numbers or markers.

Analog Digital
A watch that displays time in both a digital format and with the hands of a conventional watch. Usually featured on sport watch styles.

Annual Calendar
A watch feature that shows the day, date, month and time, adjusting automatically for short and long months.

Aperture
Some watch dials have small openings, called apertures, in which certain indications (such as the date, hour, etc.) are provided.

Atmosphere (Atm)
Unit of pressure used in watch making to indicate water resistance.

Atomic Time Standard
An extremely accurate time that is measured by the U.S. National Institute of Standards and Technology, Time and Frequency Division in Boulder, Colorado, through vibrations of atoms in a metal isotope that resembles mercury. Radio waves transmit this exact time throughout North America and some “atomic” watches can receive them and correct to the exact time. To synchronize your watch with atomic standard time, contact us for the phone number.

Automatic Watch/Automatic Movement/Automatic Winding
Also called “self-winding,” a watch with automatic movement needs no battery. The mechanism winds itself by the motion of the watch wearer’s arm. Most automatic watches have up to 36 hours of power reserve. If an automatic watch is not worn for a day or two, it will wind down and need to be wound by hand to get it started again. Typically, an automatic watch is more expensive than a quartz watch.

Baguette
Ladies style watch with a thin, elongated face; usually rectangular in shape but may be oval.

Band
The bracelet or strap that holds a watch on your wrist.

Battery-less Quartz
A modern hybrid watch technology that uses a quartz movement powered by a small electric current generator operated by a rotor. Like an automatic watch, these must be worn regularly to keep up their electrical power reserve. Also known under various marketing names, including Kinetic (Seiko), Omega-matic (Omega), and Auto quartz (Invicta).

Battery Life
The minimum period of time that a battery will continue to provide power to run a watch. Battery life begins when the factory initially installs the battery.

Battery Reserve Indicator or End of Battery Life
Some watches have a feature—often a movement of the second hand--that lets you know when the battery is approaching the end of its life.

Bezel
The ring that surrounds the watch face and holds the crystal in place. A sports or divers watch could have a rotating bezel to be used as a timer.

Bidirectional Rotating Bezel
A bezel that can be used for mathematical calculations or keeping track of elapsed time through either a clockwise or counter clockwise movement.

Bracelet
A metal band consisting of assembled links that can be removed to adjust the fit of a watch. There are also one-piece expansion style bracelets that do not have a buckle.

Cabochon
A smooth round or oval convex-shaped, polished gemstone. In watch terminology, it describes a decorative stone set in the watch.

Calendar
A watch feature that shows the date and sometimes the day of the week and the month.

Case (or Watchcase)
The metal housing of a watch's parts. Stainless steel is the most common type, but titanium, gold, silver, and platinum are also used.

Case Back
The cover for the back of the watchcase that is removed to access the watch movement for service.

Chronograph
A multifunction sport watch with a stopwatch function. Most have two or three sub-dials, or mini-dials, for measuring minutes and hours.

Chronometer
The chronometer indicates that the watch is in perfect running condition with high degree of precision according to the Official Swiss Chronometer Testing Institute standards.

Clasp
The attachment used to connect the two ends of the watch bracelet or strap around the wrist.

Countdown Timer
Lets the wearer keep track of the time remaining in a preset period. Particularly useful for sporting events.

Crown
The ridged winding knob on the right side of the case that is used to set the time (and date). On a manual watch the crown doubles as the winding mechanism to power the watch.

Crystal
The clear cover over the watch face or dial. Crystals can be made of mineral, synthetic sapphire, plastic, or acrylic material. The sapphire crystal is the most durable.

Crystal Skeleton Case back
A Case back made of transparent material that reveals the intricate movement of the watch.

Cyclops (Magnified Window)
A small window or lens in the crystal that is added to magnify the date 2 1/2 times.

Day/date Watch
A watch that indicates the date and day of the week.

Dial
The watch face.

Digital Watch
A watch that shows the time through changes of digits rather than with hands on the dial.

Diver’s Watch
Designed and manufactured especially for divers whose lives depend on the reliability of their watch in the water. Divers watches traditionally feature a graduated, rotating bezel, screw down winding crown, and must be water resistant to at least 200m or 660 feet.

Deployment Clasp
A feature found on most quality watches with metal or gold bracelets use to tighten the bracelet to the wrist. The typical clasp has two pieces of steel that clip safely beneath one long elegant looking piece of steel. All manufacturers have slightly different versions and features.

Depth Alarm
An alarm on a diver's watch that sounds when the wearer exceeds a preset depth. In most watches it stops sounding when the diver ascends above that depth.

Depth Sensor/Depth Meter
A device on a diver's watch that determines the wearer's depth by measuring water pressure. It shows the depth either by analog hands and a scale on the watch dial or through a digital display.

End of Battery Life Indicator (EOL)
The EOL indicates when it is time to replace the existing battery.

Elapsed Time Rotating Bezel
A graduated rotating bezel used to keep track of periods of time.

Engine Turning
Decorative engraving, usually on a watch dial.

Face
The visible side of the watch where the dial is contained, most are printed with Arabic or Roman numerals.

Fly-back
An additional hand on a chronograph which moves with the second hand but, can be stopped independently to measure an interval and can then "fly back" to catch up with the other hand. This is useful for capturing lap times without losing the ability to capture the finish time.

Fold-over Buckle (Deployment)
A three-folding enclosure that secures the two ends of the bracelet. When closed, the buckle covers the two-piece folding mechanism.

Function
The term used to describe the different tasks each watch component performs.

Gasket
A rubber or plastic ring that seals the internal works of the watch against dust, moisture and water.

GMT (Greenwich Mean Time) Time zone
Also known as Zulu Time, as set to the international clock in Greenwich, England, GMT reflects the world time on a 24-hour scale and is used by pilots worldwide.

Gold
Yellow precious metal, which is stainless and very malleable. Used in alloys to make jewelry, bracelets and watches. The portion of gold in the alloy is indicated in karats (k).

Gold Plating
An application of gold over the surface of an item.

Hands
The pointing device anchored at the centre and circling around the dial indicating hours, minutes, seconds and any other special features of the watch.

Hourly Time Signal
Single beep/chime, which rings on the hour, every hour when it is engaged.

Hand winding (Manual Mechanical)
A watch with a manual mechanical movement that must be wound by the wearer using the crown.

Jewels
Bearings that are usually made of synthetic sapphires or rubies in a mechanical watch. The jewels reduce friction and make the watch more accurate and longer lasting. These jewels do not add any monetary value to a watch.

Jump Hour Indicator
A jump hour indicator takes the place of an hour hand. It shows the hour by means of a numeral in a window on the dial of the watch. The minutes and seconds in a jump hour watch are read as normal from the analog hands and dial.

Keeper
A small loop on the strap near the buckle. It holds the strap end in place after the buckle has been fastened.

Kinetic
Based on a revolutionary technology, Seiko Kinetic® watches run entirely on energy generated from natural movement of the wearer’s wrist. It never needs a battery.

LCD
Liquid-crystal display. Digital time display.

LED
Light emitting diodes. Displays the time in a red light. Found less frequently these days.

Lap Memory
The ability, in some quartz sport watches, to preserve in the watch's memory the times of laps in a race that have been determined by the lap timer.

Lap Timer
A chronograph function that lets the wearer time segments of a race.

Lighted Dials
Several types of lighted dials are used so that you can tell time in the dark. A side button activates the light.

Links
The individual attached components that make up metal bracelets.

Lugs
The metal holdings used to attach the bracelet or strap to the case with pushpins.

Luminous
Luminous hands and/or hour markers are standard features on most watches that enable you to tell the time in insufficient light.

Magnified Window (Cyclops)
A small window or lens in the crystal that is added to magnify the date 2 1/2 times.

Manual Winding
The watch must be wound by turning the crown back and forth until resistance is met—usually every 24 hours.

Mechanical Movement
A watch's mechanism that is powered by a manual activity such as being wound up by hand or by the movement of the watch.

Mineral Crystal
Watch crystal made from what is essentially a form of glass. More scratch resistant than acrylic, a mineral crystal can scratch and is extremely difficult to polish.

Moon Phase
An indicator that keeps track of the phases of the moon.

Mother-of-Pearl
Iridescent, milky interior shell of the fresh water mollusk that is sliced thin and used on watch dials. While most have a milky white luster, mother-of-pearl also comes in other colors such as silvery gray, gray blue, pink, and salmon.

Movement
The inner workings or assembly that make up the main timekeeping mechanism. Movements are either quartz or mechanical. This is the engine of the watch.

O-Ring
Used to seal watch mechanisms to ensure water resistance.

Pedometer
A device that counts the number of strides taken by the wearer.

Perpetual Calendar
A type of calendar that automatically adjusts for months of different lengths and indicates February 29 in each leap year.

Platinum
One of the rarest precious metals, platinum is also one of the strongest and heaviest, making it a popular choice for setting gemstone jewellery and watches. It has a rich, white luster, and an understated look. Platinum is hypoallergenic and tarnish resistant. Platinum used in jewellery and watches is at least 85 to 95 percent pure. Many platinum watches are produced in limited editions due to the expense and rarity of the metal.

Power Reserve
A measure of the amount of time a watch will run after being fully powered or wound, with no additional power input.

Power Reserve Indicator
A feature that shows when the watch will soon need a new battery or winding.

Pulsimeter
A feature on a chronograph watch that measures pulse rate.

Push Pins
Spring action pins that attach the band to the case lugs.

Pushers/Push Pieces
Button located on the case of multifunction watches used to operate the special functions.

Quartz Movement
A watch with a mechanism powered by a "quartz crystal." The crystal vibrates when placed in an electronic field, thus powering the watch. Most affordable watches today have Quartz movements. Quartz watches are mostly battery operated.

Rattrapante (Fly-back) Chronograph
A chronograph with an additional hand that moves with the second hand but, can be stopped independently to measure an interval and can then fly back to catch up with the other hand. This is useful for capturing lap times without losing the ability to capture the finish time.

Ratchet Bezel Ring
A bezel ring that can either turn one way (counter-clockwise) or both ways and generally clicks into place.

Register
Another name for a sub-dial; this is usually a dial within the main dial of a watch.

Repeater
A device that chimes the time when the wearer pushes a button.

Retrograde
Used to describe a pointer hand on a watch dial, which returns to zero at the end of a prescribed period. For example a watch may have retrograde date - in this case the hand moves up a scale a day at a time, pointing to the current date - when it reaches 31 it will spring back to 1

Rhodium Plated
Protective coating of metal with a thin layer of rhodium--a hard, brittle metal which does not oxidize and is malleable only when red hot.

Rose (or Pink) Gold
A softly hued gold that contains the same metals as yellow gold but with a higher concentration of copper in the alloy.

Rotating Bezel
A bezel that can be turned to perform various functions.

Rotor
The part that rotates in automatic (self winding) movements and winds the main spring.

Sapphire Crystal
Highest quality transparent that is scratch resistant under normal conditions.

Screw-Down Locking Crown
A crown that aids water resistance by sealing to the case of the watch.

Second Time Zone Indicator
An additional dial that can be set to the time in another time zone. It lets the wearer keep track of local time and the time in another country simultaneously.

Self-Winding
This term refers to a mechanically powered watch that is wound by the motion of the wearer's arm rather than through turning the winding stem.

Shock Resistance
Specified on a watchcase, it means that a watch can withstand normal wear and tear, even during strenuous sport activities.

Slide Rule Bezel
A rotating bezel around the outside edge of the watch case that is printed with a logarithmic scale and assorted other scales and is used in conjunction with fixed rules of mathematics to perform general mathematical calculations or navigational computations.

Solar-powered
A type of quartz movement where the batteries are recharged via solar panels on the watch face. They have a power reserve so they can run even in the dark.

Solar Tech
Solar powered quartz watch. This technology provides the accuracy of quartz, without the inconvenience and cost of regular battery changes.

Split Second
A feature on a chronograph that actually is two hands, one a fly-back, the other a regular hand. To time laps or different finishing times, the wearer can stop the fly backhand independently while the regular hand keeps moving.

Stainless Steel
An extremely durable metal alloy that is virtually immune to rust, discoloration, and corrosion; it can be highly polished, thus resembling a precious metal. Because of its strength, stainless steel is often used even on case backs on watches made of other metals.

Sterling Silver
A white and highly reflective precious metal. Sterling refers to silver that is 92.5 percent pure, which should be stamped on the metal, sometimes accompanied by the initials of the designer or country of origin as a hallmark. Although less durable than stainless steel and other precious metals, sterling silver is often employed in watches that coordinate or look like sterling jewellery. A protective coating may be added to prevent tarnish.

Stopwatch
A watch with a second hand that measures intervals of time. When a stopwatch is incorporated into a standard watch, both the stopwatch function and the timepiece are referred to as a "chronograph."

Strap
A watchband made of leather, plastic, fabric or other non-metal material.

Sub-dial
A small dial used for any of several purposes, such as keeping track of elapsed minutes or hours on a chronograph or indicating the date.

Swiss A.O.S.C. (Certificate of Origin)
A mark identifying a watch that is assembled in Switzerland with components of Swiss origin.

Tachometer /Tachymeter
Common feature in chronograph watches. Measures the speed over a predefined distance.

Tank Watch
A rectangular watch with heavier bars on either side of the dial. Inspired by the tank tracks of World War I and first created by Louis Cartier.

Tantalum
A metal with a texture similar to titanium, but a colour similar to gold. Used by Omega for the gold-like trim on certain titanium watches. Many of these watches are also available in titanium with real gold trim.

Telemeter
A watch function that finds the distance of an object from the wearer by measuring how long it takes sound to travel the distance.

Titanium
The "space age" metal, often with a silvery-gray appearance. Because it is 30 percent stronger and nearly 50 percent lighter than steel it has been increasingly used in watch making, especially sport watch styles. Its resistance to salt water corrosion makes it particularly useful in diver's watches. Since it can be scratched fairly easily, some manufacturers use a patented-coating to resist scratching.

Tonneau Watch
A watch with a barrel-shaped watchcase and two convex sides.

Unidirectional Rotating Bezel/Unidirectional Turning Bezel
An elapsed time rotating bezel, often found on divers watches, that moves only in a counter clockwise direction. It is designed to prevent a diver who has unwittingly knocked the bezel off its original position from overestimating his remaining air supply.

UTC
Universal Time Coordinated. A universal time based on the Greenwich Meridian used by the military and in aviation. Greenwich Mean Time (GMT) can be considered approximately equivalent to Universal Time Coordinated (UTC). GMT as such is now obsolete however, being replaced by UTC. Using this time zone/standard avoids errors and problems associated with different time zones and summer times operational in different countries.

Watch Winder/Watch Winding Case/Watch Rotor/Watch Rotators
A watch winder is a mechanical device used to maintain the winding on an Automatic Watch. Automatic watches require constant wearing or they need to be placed in a watch winder box to maintain the winding and settings of the automatic watch. A watch winder allows you to own more than one automatic watch and not have to worry about resetting the time on any of them.

Waterproof
An illegal and misused term: No watch is fully 100 percent waterproof.

Water Resistance
Describes the level of protection a watch has from water damage. .A watch bearing the inscription "water-resistant" on its case back can handle light moisture, such as a rainstorm or sink splashes, but should not be worn swimming or diving. If the watch can be submerged in water, it must state at what depth it maintains water-resistance, i.e. 50 meters (165 feet) or more on most sport watches. Below 200 meters, the watch may be used for skin diving and even scuba diving depending upon the indicated depths.

Watches come in different water resistant depths and diver's depths:

Water resistant: Will withstand splashes of water or rain but should not be worn while swimming or diving.
Water tested to 50 meters (165 feet): Suitable for showering or swimming in shallow water.
Water tested to 100 meters (330 feet): Suitable for swimming or snorkelling.
Water tested to 150 meters (500 feet): Suitable for snorkelling.
Water tested to 200 meters (660 feet): Suitable for skin diving.
Diver's to 150 meters: Meets ISO Standards and is suitable for scuba diving.
Diver's to 200 meters: Meets ISO Standards and is suitable for scuba diving.

White Gold
Created from yellow gold by incorporating either nickel or palladium to the alloy to achieve a white colour. Most watches made of white gold will be 18ct.

Winding
Operation consisting of tightening the mainspring of a watch. This can be done by hand (by the crown) or automatically (by a rotor, which is caused to swing by the movements of the wearer's arm).

Winding Stem
The button on the right side of the watchcase used to wind the mainspring. Also called a "crown".

World Time Dial
A dial, usually on the outer edge of the watch face, which tells the time in up to 24 time zones around the world.

Yacht Timer
A countdown timer that sounds warning signals during the countdown for a boat race.

Yellow Gold
The traditionally popular gold - Yellow gold watches may be found in 14ct or, as found from most European manufacturers in 18ct.