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

The second-by-second choreography, with two female helpers directing judges and winners where to stand to the millimeter, added to the clockwork precision. — Mark Schilling, Variety, 4 Nov. 2026

Instead of large backlit zones lighting up behind the panel to make the display glow, mini-LED technology shrinks the backlighting zones down to just a few millimeters across. — Brian Westover, PC Magazine, 4 Nov. 2026

Microplastics are tiny pieces of plastic less than 5 millimeters long. — Don Sweeney, Sacbee.com, 3 Nov. 2026

Since even before 1996, the federal government has auctioned licenses to use select bands of the radio, microwave, and millimeter-wave spectrum for communications and broadcasting. — IEEE Spectrum, 2 Nov. 2026

Word History

Etymology

French millimètre, from milli- + mètre meter

First Known Use

1797, in the meaning defined above

Rhymes for millimeter

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

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