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
Noun
Microplastics — particles that range from 1 micrometer to 5 milimeters in size — have been documented in bottled and tap water for several years. Corinne Purtill, Los Angeles Times, 8 Jan. 2024 These tiny particles, measuring less than 2.5 micrometers in diameter or roughly 4% of the width of a strand of hair, are small enough to be breathed deep into the lungs and can enter the bloodstream. NBC News, 8 June 2023 For reference, the diameter of a human hair is about 70 micrometers. Sara Moniuszko, CBS News, 10 Jan. 2024 Given that polarons can last for about 11 nanoseconds, the scientists think that acoustic exciton-polarons could cover more than 25 micrometers before scattering. IEEE Spectrum, 6 Nov. 2023 Then, the device pushes the electrons down a colonnade: two rows of several hundred silicon pillars, each just 2 micrometers tall, with an even smaller gap between the rows. Rahul Rao, Popular Science, 2 Nov. 2023 For example, for a lidar that operates at a wavelength of 1,550 nm, the phase shifters must be placed just 1.5 micrometers apart to enable a 60-degree steering range. Michael Watts, IEEE Spectrum, 20 Aug. 2023 That includes everything from floating particles smaller than 10 micrometers (PM10) like dust and wildfire smoke to particles 2.5 micrometers (PM2.5) or smaller, like gas fumes. Boone Ashworth, WIRED, 25 Aug. 2023 The specimen recovered from the meteorite was about 40 micrometers across, just the width of a human hair, but the metal could help revolutionize global production of electronics—everything from iPhones to fighter jets. Andrew Zaleski, Popular Mechanics, 22 Aug. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'micrometer.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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 24 Feb. 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

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