speed-measuring instrument, 1810, coined by inventor, Bryan Donkin, from tacho- "speed" + -meter. Related: Tachometry.
Entries linking to tachometer
tacho-
word-forming element meaning "speed," from Latinized form of Greek takho-, combining form of takhos "speed, swiftness, fleetness, velocity," related to takhys "swift," of unknown origin.
-meter
word-forming element meaning "device or instrument for measuring;" commonly -ometer, occasionally -imeter; from French -mètre, from Greek metron "a measure," from PIE root *me- (2) "to measure."
speedometer n.
1904, from speed + -meter. A Germanic-Greek hybrid and thus much execrated.
[T]he ancient Greeks & Romans knew what speed was, & yet no-one supposes they called it speed, whence it follows that speedo- & speedometer are barbarisms. [Fowler]