Definitions

1. noun

An instrument for measuring the rate of rotation or speed of an engine, vehicle, or other machine.

“The mechanic used a tachometer to check the car’s engine speed before the repair.”

2. noun

A device used to measure the speed of an athlete, typically a runner, in events such as track and field.

“The coach used a tachometer to monitor the athlete’s speed during the 400-meter dash.”

3. noun

A device for measuring the rate of rotation or speed of a mechanical system, such as a gear or a shaft.

“The engineer used a tachometer to measure the speed of the gear during the experiment.”