millimeter

noun

mil·​li·​me·​ter ˈmi-lə-ˌmē-tər 

variants US millimeter or British millimetre

: a unit of length equal to ¹/₁₀₀₀ meter see Metric System Table

Examples of millimeter in a Sentence

Recent Examples on the Web

Most of the time, these sensors track very slow movement, on the order of millimeters or less per year. —Rong-Gong Lin Ii, Los Angeles Times, 5 June 2024

Shield did not detect small lesions of less than 10 millimeters. —Mary Kekatos, ABC News, 24 May 2024

When shopping for compression socks, podiatrist Salma Aziz, DPM, MS, says pregnant people should start with a mild compression of 15-20 millimeters of mercury (mmHg). —Laura Lu, Ms, Parents, 21 May 2024

Scanning each of these targets took eight minutes or less for image resolutions of roughly 2 by 2 by 8 cubic millimeters. —IEEE Spectrum, 15 May 2024

Word History

Etymology

French millimètre, from milli- + mètre meter

First Known Use

1797, in the meaning defined above

Kids Definition

millimeter

noun

mil·​li·​me·​ter ˈmil-ə-ˌmēt-ər 

: a measure of length equal to ¹⁄₁₀₀₀ meter see metric system table

Medical Definition

millimeter

noun

mil·​li·​me·​ter

variants or chiefly British millimetre

ˈmil-ə-ˌmēt-ər 

: one thousandth of a meter

—abbreviation mm