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 joining pads must be precisely aligned to within less than a micrometer for the process to work. — Alex Music, IEEE Spectrum, 25 June 2026 Hyphae are often barely five micrometers wide — about one-tenth the width of a human hair and much narrower than a plant’s root tip. — Quanta Magazine, 6 Apr. 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 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

Rhymes for micrometer

See All Rhymes for micrometer

Browse Nearby Words

micrometeorology
micrometer
micrometer caliper
See all Nearby Words

Cite this Entry

“Micrometer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/micrometer. Accessed 8 Jul. 2026.

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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
: micrometer caliper
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
ˈmī-krō-ˌmēt-ər How to pronounce micrometer (audio)
: micron

More from Merriam-Webster on micrometer

Nglish: Translation of micrometer for Spanish Speakers

Britannica.com: Encyclopedia article about micrometer

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