Glossary
Analogue – A display which uses continuously moving hands to represent the time
Arabic numerals – Numerals expressed traditionally from 1-12
Atmosphere (ATM) – A unit in describing water resistance. 10 metres of water is equivalent to an additional atmosphere of pressure acting on the watch. This unit applies to a stationary watch. A watch in motion in water will experience greater pressure.
Automatic – A watch movement which winds the mainspring when the watch is moved, with a weighted rotor.
Band – A type of strap; a strip of material to which the watch is attached by the lugs
Bangle – A jewellery-like bangle with a watch attached.
Battery – Provides the electrical current which a quartz watch movement requires to operate.
Bezel – The part of the case which surrounds the watch dial.
Buckle – The mechanism which fastens the watch strap.
Caliber – a specific model of watch movement.
Case – the body of the watch, which contains the watch mechanism and dial.
Chronograph – a stopwatch complication which allows the user to track two different times simultaneously.
Chronometer – a watch which has been certified to precision standards. Swiss-made watches must be tested by the COSC, and meet exacting standards of construction and accuracy to be considered a Chronometer.
Complication – an additional function of a watch.
COSC. – Contrôle Officiel Suisse des Chronomètres – a Swiss group which assesses whether a watch can be considered a Chronometer.
Crown – the circular protrusion from the outside of the case, attached to the mainspring. Used to set the time/wind the watch.
Crystal – Covering of the watch face.
Dial – the section of the watch which displays the time.
Digital – a display which uses discretely changing numerals instead of continuously moving hands.
Deployment buckle – a folding buckle.
Dual time – a watch which with a second hour hand, to display the time simultaneously from two time zones.
Ébauche – an unassembled watch movement.
Escapement – a component in the movement which transfers power from the mainspring to the regulator, therefore maintaining accurate time. The notched wheel train and anchor form part of the movement.
Foldover clasp – a clasp which collapses on itself , often closing with a safety catch.
GMT – Greenwich Mean Tine, which provides the basis for determining worldwide time zones by adding or subtracting hours for different time zones.
Grand complication – Features three major complications in its movement.
Guilloche – A fine engraving technique sometimes used on watch dials or to decorate watch movements. Achieved with a repetitive turning machine.
Hand-wound – A mechanical watch which requires the user to wind the mainspring. Usually accomplished by twisting the crown back and forth while it’s flush with the watch case.
Horology – The study of time.
Indices – The symbols other than numerals used to denote the hour points on a watch face.
Jewels – Used in mechanical watches. Jewels are industrial rubies with a polished finish, incorporated into the bearings of the mechanism where pieces of metal need to rotate or move over each other smoothly. These jewels have a low surface friction, so can keep the mechanism moving smoothly without extra lubrication.
LCD (Liquid Crystal Display) – Dial type on digital watches, which uses an electrical field to form letters or numerals to regulate timekeeping.
Light – An illumination function incorporated into the dial to enable the watch to be read in low light.
Links – These form part of the bracelet and can be removed in order to adjust the length to fit your wrist.
Lugs – The “arms” which protrude from the top and bottom of the watch case. Each lug features a drilled hole. A telescoping pin is pushed through the watch strap, and then fixed into place between the two lugs.
Mainspring – The primary spring in a watch where the potential energy is stored. Gradually releases over time, regulating the time and providing energy for the movement. The watch will stop when the mainspring is fully unwound.
Mechanical – A watch movement that operates without batteries, using only moving parts such as cogs, levers and springs.
Moonphase – A complication which tracks the waxing or waning of the moon. Although sometimes used as a decorative feature, the moonphase can be used to infer information on the tides, or to provide an indication of how much moonlight there will that night.
NATO strap – A fabric watch strap, that adds a more casual feel to a watch.
Numerals – Used to denote the hour points on the watch face, traditionally either Arabic (1 – 12) or Roman (I to XII).
Perpetual calendar- A watch complication that tracks and displays the day, date, month and year without requiring resetting for shorter months or leap years.
Pin buckle – The simple pin-and-hole fastening used on leather watch straps.
Physical Vapour Deposition (PVD) – A method of coating a watch with a film of vaporised metal. PVD coatings provide an even coverage which is harder and more resistant to abrasion than electro-plated metals.
Power reserve indicator – Mechanical watches store potential energy in the mainspring. A power reserve indicator records and displays how wound up the mainspring is, providing a warning for when it needs winding.
Quartz – A watch movement that uses a battery running a current through a quartz crystal. Keeps extremely accurate time, but relies on the battery having a charge.
Radio-controlled – These watches receive radio-controlled signals from a satellite transmitter to ensure highly accurate timekeeping. Radio-controlled watches are accurate to within one second.
Retrograde – A display which resets back to zero once the cycle has completed.
Rotating bezel – A watch bezel which can be rotated, instead of remaining static.
Roman numerals – Hour markers of I – XII.
Rotor – An eccentrically-weighted piece of metal that spins about when an automatic watch moves, providing the distinctive weight and sense of internal movement of an automatic watch.
Skeleton – Describes watch cases of dials which use a transparent surface where an opaque surface would traditionally be used. A skeleton dial is see-through, allowing the movement to be visible behind the hands.
Shock-resistant – A watch designed to withstand gentle jolts during sport or leisure activities.
Sub-dial – A smaller dial set inside the main watch dial.
Tachymeter – A numerical scale around a watch bezel, which can be used to calculate speed or distance of a moving object.
Unidirectional bezel – A movable bezel with markings which can be used to measure elapsed time since a starting point.
Waterproof – The International Organisation for Standardisation prohibits the use of the term “waterproof” when describing watches.
Water resistance – A laboratory-assessed standard that details how well a watch can be expected to resist exposure to water without leaking. Based on submersion of the watch in static water, it’s measured in intervals of 10 metres / 1 ATM. Diving watches must be 100m / 10ATM water resistant.