- a mechanical or electrical instrument that makes repeated clicking sounds at an adjustable pace, used for marking rhythm, especially in practicing music.
- a mechanical device which indicates the exact tempo of a piece of music by producing a clicking sound from a pendulum with an adjustable period of swing
n.mechanical musical time-keeper, 1815, coined in English from comb. form of Greek metron “measure” (see meter (n.2)) + -nomos “regulating,” verbal adjective of nemein “to regulate” (see numismatics). The device invented 1815 by Johann Maelzel (1772-1838), German civil engineer and showman. Related: Metronomic.