any of various instruments for measuring or indicating velocity or speed, as of a machine, a river, or the blood.
an instrument measuring revolutions per minute, as of an engine.
Origin of tachometer
Related formstach·o·met·ri·cal·ly [tak-uh-me-trik-lee] /ˌtæk əˈmɛ trɪk li/, adverbta·chom·e·try, noun
First recorded in 1800–10; tacho-
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for tachometer
Historical Examples of tachometer
His clock and his tachometer assured him that he was well past Easton.
He watched his tachometer, which indicated his revolutions per minute.
I guess the first thing that Lindy watched was the tachometer.
There is a gear which serves to drive the magnetos and tachometer, also the air pump.
A tachometer was also employed to observe the number of turns that the screw was making in a minute.
British Dictionary definitions for tachometer
Derived Formstachometric (ˌtækəˈmɛtrɪk) or tachometrical, adjectivetachometrically, adverbtachometry, noun
any device for measuring speed, esp the rate of revolution of a shaft. Tachometers (rev counters) are often fitted to cars to indicate the number of revolutions per minute of the engine
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for tachometer
1810, from Greek tachos "speed" + -meter.
Online Etymology Dictionary, © 2010 Douglas Harper
An instrument used to measure the rotations per minute of a rotating shaft.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.