Glossary of Watch Terms

Automatic (self-winding) 

A style of watch that has a main spring that is wound by the movement of the wearer’s wrist. This is accomplished by means of a rotor inside the watch that swings freely on its arbor to wind the main spring. 

Chronograph 

This is a very popular style of watch that has an additional complication that allows time to be measured in short periods (much like a stop-watch) without it affecting the main time keeping mechanism. Most chronographs feature sub-dials for seconds, minutes, and hour(s).

Complication 

In horology terms, a complication in a mechanical timepiece is any feature beyond that of a simple hours, minutes, and seconds movement such as a moon phase, month display, quickset date, power reserve, chronograph, etc.

Ébauche 

Ébauche is a French term meaning “outline” or “blank”. In horology the term refers to an incomplete watch movement. The modern “ébauche” is a jewelled watch movement, without its regulating organs, mainspring, dial, or hands.

ETA Movement 

ETA is a Swiss producer of mechanical and quartz watch movements and also manufactures clock movements, as well. It is a wholly owned subsidiary of the Swatch Group.

Luminescent Hands/DIals 

Hands and indicies on a watch that glow in the dark after being “charged” by a light source (usually a strong light for 30 seconds or so).

Manual (hand-wound) Movement 

Simply a watch whose main spring must be wound manually by turning or rotating the crown.

Mineral Crystal 

Basically fancy name for hardened glass used to make scratch resistant watch crystals.

Sapphire Crystal 

Sapphire is used to make a totally scratch proof watch crystal. Only a diamond is able to scratch sapphire.

Skeleton Watch 

This is a watch in which various parts of the movement and dial have been reduced to a minimum by removing the bulk of the metal thereby enabling the parts of the movement to be seen. Most always this watch will have an exhibition (see-through) back.

Tourbillon 

A watch escapement invented in 1795 by Abraham-Louis Breguet that is designed to counter the effects of gravity and other perturbing forces that can affect the accuracy of a chronometer. The tourbillon is considered to be the most complex of watch complications and is valued for its engineering and design principles.