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

Still, some people saw their SBP drop by 1.24 millimeters of mercury (mm Hg) after taking turmeric for 12 weeks. —Patricia Weiser, Pharmd, Verywell Health, 29 Apr. 2025

Again, not a spoonful of dirt has been removed nor has a millimeter of rail been put in place. —Reader Commentary, Baltimore Sun, 26 Apr. 2025

The eggs appear like tiny bits of dirt to the naked eye and are about half a millimeter in size. —Caelyn Pender, Mercury News, 25 Apr. 2025

The 1080 isn’t quite a max cushion shoe, but its 30-plus millimeters of foam in the sole may be a bit too much for runners who like to feel the ground. —Lauren Wingenroth, SELF, 25 Apr. 2025

Word History

Etymology

French millimètre, from milli- + mètre meter

First Known Use

1797, in the meaning defined above

Rhymes for millimeter

• amphitheater
• centimeter
• centimetre
• decimeter
• ergometer
• expositor
• gasometer
• gravimeter
• hexameter
• manometer
• milliliter
• millimetre

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