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

Trump survived by millimeters a would-be assassin’s bullet at a rally in Butler, Pennsylvania. —Bill Barrow, Fortune, 4 Nov. 2024

The walls are lined with 50 millimeter fiberglass insulation cotton, providing great thermal and sound insulation. —Toni Sutton, People.com, 2 Nov. 2024

Pitt’s pilot, Phillip McKenzie, has two motor arrays implanted in his brain, each the size of a pencil eraser, with 100 electrode tips that go a millimeter and a half into the brain. —Dana MacKenzie, Smithsonian Magazine, 23 Oct. 2024

Micrometeoroids are minuscule pieces of dust, molecules to millimeters in scale, that drift through space. —Jonathan O’Callaghan, Discover Magazine, 21 Oct. 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