micrometer

1 of 2

noun (1)

mi·​crom·​e·​ter mī-ˈkrä-mə-tər 

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

• micrometer 2

micrometer

2 of 2

noun (2)

mi·​cro·​me·​ter ˈmī-krō-ˌmē-tər 

: 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

Their current fibers measure about 1 millimeter across, but improved fabrication methods could reduce that thickness to tens of micrometers. — Aamir Khollam, Interesting Engineering, 9 Oct. 2026

At the same 5-GHz frequency, a sound wave's wavelength collapses from centimeters, as is the case with light, to a couple of micrometers, roughly four orders of magnitude smaller. — New Atlas, 23 Sep. 2026

Twelve-micrometer polystyrene films got punched through while 130-micrometer films survived. — Jacek Krywko, ArsTechnica, 31 Aug. 2026

The front of the skimmer has an impeller that sucks in debris and holds it in a removable four-liter basket with a screen that captures particles as small as 150 micrometers (uM) such as hair, sand, and dust. — John R. Delaney, PC Magazine, 6 Aug. 2026

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

Rhymes for micrometer

• barometer
• chronometer
• geometer
• hydrometer
• hygrometer
• kilometer
• odometer
• photometer
• psychrometer
• pycnometer
• pyrometer
• rheometer

Kids Definition

micrometer

1 of 2 noun

mi·​crom·​e·​ter mī-ˈkräm-ət-ər 

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 

: 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 

: 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 

: micron