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 teen, who suffered four days of stomach pain before being admitted to Tauranga Hospital, had ingested between 80 and 100 high-power magnets, each around 5×2 millimeters in size, according to a Friday report in the New Zealand Medical Journal. —Sophia Compton, FOXNews.com, 24 Oct. 2025

The lower body and tail had the largest polygonal scales, although most were tiny pebble-like scales just 1–4 millimeters across, surprisingly small for a dinosaur growing to over 40 feet in length. —Abhishek Bhardwaj, Interesting Engineering, 24 Oct. 2025

The process brings hemp fibers down to 35 millimeters so it can be spun in a blend on existing cotton spinning systems. —Angela Velasquez, Sourcing Journal, 23 Oct. 2025

Repetition builds finesse in delicate, millimeter-level procedures. —Wyles Daniel, USA Today, 22 Oct. 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