tachometer

American  

[ta-kom-i-ter, tuh-] / tæˈkɒm ɪ tər, tə- /

noun

1. any of various instruments for measuring or indicating velocity or speed, as of a machine, a river, or the blood.

2. an instrument measuring revolutions per minute, as of an engine.

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tachometer British  

/ ˌtækəˈmɛtrɪk, tæˈkɒmɪtə /

noun

1. 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

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Other Word Forms

• tachometric
  adjective
• tachometrically
  adverb
• tachometry
  noun

Etymology

Origin of tachometer

First recorded in 1800–10; tacho- + -meter

Example Sentences

Watch as the graphically animated tachometer needle fans through a couple of full-power upshifts.

From The Wall Street Journal • Apr. 18, 2026

Upshift with the tachometer at 2,000 to 2,500 rpm, not 3,000, Toyota advises.

From Los Angeles Times • Mar. 10, 2022

A conventional dash with all its gauges in place, save a single unit in place of the tachometer to relay the electrical goings-ons, will be an option on retrofitted vehicles.

From New York Times • Sep. 6, 2018

Allow your eyes to dip down briefly to the tachometer.

From The Verge • Feb. 9, 2016

It is driven by a 220-volt motor connected to a tachometer which reads both meters per second and revolutions per minute.

From Transactions of the American Society of Civil Engineers, vol. LXX, Dec. 1910 Federal Investigations of Mine Accidents, Structural Materials and Fuels. Paper No. 1171 by Wilson, Herbert M.