a metronome is a form of:

Metronome



noun
1.
(a device, with an inverted pendulum, that beats time, as in setting a musical tempo) មាត្រា (ពក្យភ្លេង)
ENGLISH MEANING
noun
1.
An instrument consisting of a short pendulum with a sliding weight. It is set in motion by clockwork, and serves to measure time in music.