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
Particulate matter less than 2.5 micrometers in size, PM2.5, sits at a concentration around 40 micrograms per cubic meter in Stockton, but the 2020 August Complex fires raised that level to more than 70 for multiple days. Noah Haggerty, Los Angeles Times, 1 Dec. 2024 Remarkably, all of our DNA can fit inside a cell’s nucleus, which is only a few micrometers long. William A. Haseltine, Forbes, 1 Nov. 2024 For now, the team has only printed tiny samples with a diameter of 3 centimeters, a length of 7 centimeters and a resolution of 15 micrometers, per New Scientist. Margherita Bassi, Smithsonian Magazine, 19 Nov. 2024 Ultrafine particles are aerosols less than 0.1 micrometers, or 100 nanometers, in diameter — about one-thousandth the width of a human hair. Discover Magazine, 1 Nov. 2024 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

Dictionary Entries Near micrometer

Cite this Entry

“Micrometer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/micrometer. Accessed 13 Dec. 2024.

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

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