tachometer
/taˈkɒmɪtə
/noun
An instrument which measures the working speed of an engine (especially in a road vehicle), typically in revolutions per minute.Drivers watch their tachometers, which monitor RPMs, to get an idea of how fast they are going....
- I noted his tachometer, radar detector and exhaust pipe.
- The built-in tachometers and rpm-based automatic shifters that are incorporated into some delay boxes/devices may not be used for any purpose.
