metronome

noun

Etymology: Coined in English from Ancient Greek μέτρον (métron, “measure”) + νόμος (nómos, “regulation, law”).

1. A device, containing an inverted pendulum, used to mark time by means of regular ticks at adjustable intervals; an electronic equivalent that emits flashes.

   “The etudes with metronome markings should be played in tempo, all others should be considered rubato.”

   “It’s one of the earliest pieces in the comprehensive collection of metronomes by the British instrument dealer Tony Bingham, which forms the bulk of the Basel exhibition.”