Watch regulator

Wiktionary Word definitions in Wiktionary
n. The timekeeping device normally used in mechanical watches and small clocks. Consisting of a wheel which oscillates due to a coiled spring.

Wikipedia Word definitions in Wikipedia
A balance wheel , or balance , is the timekeeping device used in mechanical watches and some clocks , analogous to the pendulum in a pendulum clock . It is a weighted wheel that rotates back and forth, being returned toward its center position by a spiral ...

WordNet Word definitions in WordNet
n. a wheel that regulates the rate of movement in a machine; especially a wheel oscillating against the hairspring of a timepiece to regulate its beat [syn: balance ]

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Balance wheel \Bal"ance wheel`\ (Horology) A wheel which regulates the beats or pulses of a watch or chronometer, answering to the pendulum of a clock; -- often called simply a balance . A ratchet-shaped scape wheel, which in some watches is acted upon ...