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
Previous research shows speeds reaching 120 micrometers a second. Andrew Paul, Popular Science, 11 June 2026 Aerosolized particles can range from a few nanometers to several tens of micrometers, which could make a quick squirt of deodorant or hairspray a catastrophic event. Victor Tangermann, Futurism, 10 June 2026 Embedded throughout these materials are microscopic magnetic particles roughly 5 micrometers in size. New Atlas, 8 June 2026 So the Zurich robotics team engineered microscopic machines about six micrometers wide – smaller than a red blood cell. Will Barker, TheWeek, 4 June 2026 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 18 Jun. 2026.

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

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