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a combining form meaning “speed,” used in the formation of compound words: tachometer.
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Compare tachy-.

Origin of tacho-

Combining form representing Greek táchos; akin to tachýs swift
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021


What does tacho- mean?

Tacho- is a combining form used like a prefix meaning “speed.” It is especially used in scientific terms.

Tacho- comes from the Greek táchos, meaning “speed.”

Related to tacho- is tacheo-, as in tacheometry, and tachy-, as in tachygraph.

Want to know more? Read our articles Words That Use tacheo- and Words That Use tachy-.

Examples of tacho-

An example of a scientific term that features the combining form tacho- is tachometer, a term for a variety of instruments that measure velocity or speed, such as how fast an engine goes.

The word tachometer is made of two combining forms. The first is tacho- which, as we know, means “speed.” The second is -meter which means “measure.” Tachometer translates literally to “speed-measurer.”

What are some words that use the combining form tacho-?

What are some other forms that tacho- may be commonly confused with?

And of course, tacho- has nothing to do with tacos or nachos, speedily as we may love to eat them.

Break it down!

The combining form -gram means “something written; drawing.” What, in general, is a tachogram a record of?

How to use tacho- in a sentence

  • Tacho lived a considerable time at the court of Ochus, without any steps being taken to restore him to his former position.

    Ancient Egypt|George Rawlinson

British Dictionary definitions for tacho-


combining form
speedtachograph; tachometer

Word Origin for tacho-

from Greek takhos
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