Welcome to the world of fine luxury timepieces. In order to familiarize yourself with various watch brands and its functionality, its important for you to know some of the standard terms in the industry. Here are some commonly used terms.

Opposite of digital, a watch showing the time using hands.
A small opening. Some watch dials have apertures showing the date or the watch's movement.
Automatic Watch
A watch that winds on its own.See also: Rotor
Automatic winding (or self winding)
This term refers to a watch with a mechanical movement (as opposed to a quartz or electrical movement). The watch is wound by the motion of the wearer's arm rather than through turning the winding stem. A rotor that turns in response to motion winds the watch's mainspring. 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.See also: Rotor
This might be thought of as the very basis of a watch's movement. It's a tiny moving part secured at its base with a hairspring that causes it to oscillate back and forth regularly. In each oscillation, the wheel moves one click, marking off 1/8th of a second.
The ring surrounding the watch dial and crystal.
The Control Officile Suisse de Chronometers, an independent regulatory council that tests and certifies (or fails) watch movements for chronometer status.
Usually used in reference to a decorative stone set in the watch crown. It can also mean any small gemstone.
Originally used to mean the size of a watch movement, this term now denotes a type of movement (men's calibre, automatic calibre, etc). When a calibre number is accompanied by the manufacturer's mark, it serves as an indication of origin.
A watch that includes a built in stopwatch function - i.e., a timer that can be started and stopped to time an event. There are many variations on the chronograph. Some operate with a center seconds hand which keeps time on the watch's main dial.

Others use sub-dials to time elapsed hours, minutes and seconds. Still others show elapsed time on a digital display on the watch face. Some chronographs can be used as a lap timer (see "flyback hand" and "split seconds hand"). The accuracy of the stopwatch function will commonly vary from 1/5th second to 1/100th second depending on the chronograph.

Some chronographs will measure elapsed time up to 24 hours. Watches that include the chronograph function are themselves called "chronographs." When a chronograph is used in conjunction with specialized scales on the watch face it can perform ma ny different functions, such as determining speed or distance (see "tachymeter" and "telemeter") Do not confuse the term "chronograph" with "chronometer."

The latter refers to a timepiece, which may or may not have a chronograph function, that has met certain high standards of accuracy set by an official watch institute in Switzerland.See also: Rattrapante
This term refers to the stopwatch itself, and more specifically a stopwatch with precision rigorously tested by the C.O.S.C. (see below) in Switzerland.
The attachment used to connect 2 ends of the watch bracelet around the wrist.

One or more features added to a watch in addition to its usual time-telling functions, which normally not only include the hours, minutes and seconds but also date and often the day of the week as well. Complications such as; perpetual calendars, moonphase displays, alarms, repeating mechanisms, quarter strikes as well as stop/start chronograph functions. Power reserve indicators are also usually regarded as 'complications'


A crown is the button on the outside of the watch case that is used to set the time and date. In a mechanical watch the crown also winds the mainspring which in turn, moves the hands of the watch to tell time.

A screw in (or screw down/lock) crown is used to make a watch more water resistant. The crown actually screws into the case, dramatically increasing the water-tightness of the watch. This system was first patented by Rolex in the early 20th Century.


See also: Screw-lock crown, Winding stem
Deployant Buckle or Invisible Double Locking Clasp

The Deployant Buckle or Invisible Double-Locking Clasp is also known as the Hidden Deployant Buckle or Butterfly Clasp, because, when closed, the clasp is essentially invisible and it opens symmetrically like a butterfly. This is perhaps one of the most common clasps available and most preferred by customers because the clasp is not a distraction from the watch itself. The clasp is opened by pulling the joined ends of the bracelet away from the wrist. These clasps also come on some of the leather and other non-metal strapped watches.

End of Life. In quartz movement, the second hand will start to "jump" every four seconds when the end of battery life is near.
A set of parts (i.e. the escape wheel, lever, roller) that convert rotary motion into balance.
Expansion Bracelet
The Expansion Bracelet or Band is designed to expand or stretch over the wearer's wrist and then contract snuggly on the wrist when released.
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. Start the chronograph, putting both the flyback hand and the regular chronograph seconds hand in motion. 

To record a lap time or finishing time, stop the flyback hand. After recording the time, push a button and the hand will "fly back" to catch up with the constantly moving elapsed-time hand. Repeat the process to record as many lap times or finishing times as needed.See also: Rattrapante
Fold Over Clasp
The Fold Over Clasp collapses on itself and locks via a pressure tab. The clasp typically has several micro adjustment holes (as seen in the image) that can be used to adjust the bracelet size by non-jewelers. In time, the pressure tab often wears out and the clasp no longer stays closed. This has led to the following three different improvements on the Fold Over concept.See also: Fold Over Clasp with Push Button, Fold Over Clasp with Safety and Push Button or Double Locking Fold-Over Clasp
Fold Over Clasp with Push Button
This is the second of three improvements on the Fold Over Clasp. The Fold Over Clasp with Push Button Clasp provides a secure lock on a post that can only be released by pushing the two buttons. This improvement is more secure than the Fold Over Safety Clasp.See also: Fold Over Clasp, Fold Over Clasp with Safety, Fold Over Clasp with Safety and Push Button or Double Locking Fold-Over Clasp
Fold Over Clasp with Safety
This is the first of three improvements on the Fold Over Clasp. The Fold Over Safety Clasp provides a flap that folds over the closed end of the clasp which makes the clasp more difficult to open unintentionally.See also: Fold Over Clasp with Push Button, Fold Over Clasp with Safety and Push Button or Double Locking Fold-Over Clasp
Fold Over Clasp with Safety and Push Button or Double Locking Fold-Over Clasp
This is the third of three improvements on the Fold Over Clasp. This clasp combines the flap of the safety clasp with a push button lock to provide the wearer the maximum security available for any Fold Over Clasp.See also: Fold Over Clasp, Fold Over Clasp with Push Button, Fold Over Clasp with Safety

GMT (Greenwich Mean Time), the standard for all international time.


A type of engraving in which thin (often hand machined) lines are interwoven in a pattern to form a design or artwork. This term is used on the dials of watches.


The science of time measurement.
Synthetic sapphires or rubies that act as bearings for gears in a mechanical watch. The jewels reduce friction to make the watch more accurate and longer lasting.See also: Sapphire crystal
A unit of gold fineness (and gemstone weight). Purity is 24k. 18k gold is 75% pure. Some sources distinguish carat applied only to gemstones, denoting a unit of weight. We have not seen the need to do so on this site.
Synthetic material that glows in the dark, used especially in diving watches.
Mechanical movement
A movement powered by a mainspring, working in conjunction with a balance wheel. Most watches today have electronically controlled quartz movements and are powered by a battery. However, mechanical watches are currently enjoying a resurgence in popularity.
Minute repeater

A watch which can tell the time, at the push of a button or move of a small slide on the side of the case, by striking the hours, quarter hours and minutes on small goings inside the watch. Such complex watches are very expensive.

Moonphase display

A graphic display by means of a specially shaped aperture in the dial to indicate the phase of the moon, i.e. full, new or somewhere in between. It is often represented by a blue disc with gold print of the moon & rotates underneath the dial, showing partial to full moon on the 15th lunar day.


Multi-colored shell of any fresh water mollusk, thinly sliced and used on watch dials.
The inner mechanism of a watch that keeps time and moves the watch's hands, calendar, etc. Movements are either mechanical or quartz.
Any calendar that automatically adjusts for all months and leap years.

One of the rarest and also strongest of the precious metals. It is represented with the no. 950 & often hallmarked with a goat's head.

See also: Sapphire crystal, Titanium
Power reserve indicator

A feature that shows when the watch will soon need a new battery or winding. For mechanical watches, this shows how many hours of reserve is left in the mainspring informing you to wind up the watch by winding the crown for manual winding movt & wearing it for automatic movt. A battery reserve indicator on a quartz watch informs the wearer when the battery is low. Often this is indicated by the seconds hand moving at two or three-second intervals. Seiko's Kinetic watches are quartz watches that do not have a battery (see Kinetic). When a Seiko Kinetic needs to be wound, the seconds hand will also move in two second intervals.

Any button that operates the special functions of watches.
The flyback hand of a chronograph.See also: Chronograph, Flyback Hand

A watch that indicates hours with a note or tone by pressing of a button or push of the slide on the side of the case. See minute repeater.


The half disc of heavy metal that rotates and helps wind an automatic watch.See also: Automatic Watch, Automatic winding (or self winding)
Sapphire crystal

A crystal made of synthetic sapphire, a transparent, shatter-resistant, scratch-resistant substance. However, if subjected to forced contact from hard objects, the crystal will get scratched & chipped or even crack when it hits a hard surface. Eg. dropping your watch on a hard ground. Otherwise, it can last for many years.


See also: Jewels, Platinum
Screw-lock crown
A crown that can be screwed into the case to make the watch watertight.See also: Crown, Winding stem
Shock Absorber
A bearing that takes up shocks received by the balance staff, protecting it from damage.
A small dial on a watch face used for any of several purposes, such as keeping track of elapsed minutes or hours on a chronograph or indicating the date.See also: World time dial
Swiss made
As a part of a move towards greater consumer protection and in order to combat fakes in the Far East that claim to be Swiss made, the Swiss federal council in 1993 laid down the rule that a watch has to satisfy before it could be described as Swiss made. The movement must be of Swiss origin, and must contain at least 50% Swiss parts. The watch must be cased in Switzerland and pass its final inspection in that country.

Represented by the sign Ti. It is a silver-gray "space age" metal that is both stronger and lighter than steel. It is anti-allergy & resists rust. It is roughly one-third the weight of steel.


See also: Platinum

Invented by Abraham Louis Breguet some 2 centuries ago. Often cited as the most significant development in watch history, this consists of the regulating mechanism (balance wheel with hairspring) and the lever escapement, which makes one revolution in one minute. It eliminates effects of friction and earth's gravity. Therefore, giving a more accurate time.


Water resistance

The ability to withstand splashes of water. Terms such as "water resistant to 50 meters (5 ATM)" or "water resistant to 200 meters (20 ATM)" indicate that the watch can be worn underwater to various depths. However, watches with the term 3 ATM or 30m are not suitable for diving or even swimming.


Winding stem

Also called a stem or pin, it is a tiny metal rod with screw thread that holds the crown & connects it to the movement of the watch. It is then used to set time & winding of the mainspring. You must take extra care when setting time or winding up your watch. Always remove your watch from your wrist to adjust the crown or there are chances that the winding stem will be snapped if you subject it to abnormal pressure.


See also: Crown, Screw-lock crown
World time dial
A dial, usually on the outer edge of the watch face, that tells the time in up to 24 time zones around the world. The time zones are represented by the names of cities printed on the bezel or dial. The wearer reads the hour in a particular time zone by looking at the scale next to the city that the hour hand is pointing to. The minutes are read as normal. Watches with this feature are called "world timers."See also: Sub-dial