micrometer

1 of 2

noun (1)

mi·​crom·​e·​ter mī-ˈkrä-mə-tər How to pronounce micrometer (audio)
1
: an instrument used with a telescope or microscope for measuring minute distances
2
: a caliper for making precise measurements that has a spindle moved by a finely threaded screw

Illustration of micrometer

Illustration of micrometer
  • micrometer 2

micrometer

2 of 2

noun (2)

mi·​cro·​me·​ter ˈmī-krō-ˌmē-tər How to pronounce micrometer (audio)
: a unit of length equal to one millionth of a meter

called also micron

see Metric System Table

Examples of micrometer in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
The most advanced of these are called micro-LED displays, which boast, as the name suggests, pixels on the scale of micrometers. Michael Irving, New Atlas, 30 Mar. 2025 The slice of rock mounted on the glass slide is only ~30 micrometers (~0.001 inches) thick. Erik Klemetti, Discover Magazine, 25 Mar. 2025 In their desperate meandering, some larvae—which measure 500 to 600 micrometers (0.05 to 0.06 centimeters) long—will travel several centimeters each day. Ars Technica, 21 Feb. 2025 That's because these flecks are in fact around 10 micrometers wide – or a fifth the width of a human hair. New Atlas, 4 Apr. 2025 See All Example Sentences for micrometer

Word History

Etymology

Noun (1)

French micromètre, from micr- + -mètre -meter

Noun (2)

International Scientific Vocabulary micr- + meter entry 3

First Known Use

Noun (1)

1670, in the meaning defined at sense 1

Noun (2)

1880, in the meaning defined above

Time Traveler
The first known use of micrometer was in 1670

Cite this Entry

“Micrometer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/micrometer. Accessed 29 Apr. 2025.

Kids Definition

micrometer

1 of 2 noun
mi·​crom·​e·​ter mī-ˈkräm-ət-ər How to pronounce micrometer (audio)
1
: an instrument used with a telescope or microscope for measuring very small distances
2
micrometry
-ˈkräm-ə-trē
noun

micrometer

2 of 2 noun
mi·​cro·​me·​ter ˈmī-krō-ˌmēt-ər How to pronounce micrometer (audio)
: a unit of length equal to one millionth of a meter

Medical Definition

micrometer

1 of 2 noun
mi·​crom·​e·​ter mī-ˈkräm-ət-ər How to pronounce micrometer (audio)
: an instrument used with a telescope or microscope for measuring minute distances

micrometer

2 of 2 noun
mi·​cro·​me·​ter
variants or chiefly British micrometre
: micron

More from Merriam-Webster on micrometer

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!