millimeter
Americannoun
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of millimeter
First recorded in 1800–10; from French millimètre; see milli-, meter 1
Explanation
A millimeter is a tiny unit of measurement. The thickness of a dime is a little more than a millimeter, and there are a thousand millimeters in a meter. If you're using metric units to measure the length of something, you'll be dealing in meters and variations on meters, including millimeters. Look at a ruler that includes centimeters, the units of metric measurement that are closest in length to inches. The smallest units marked on the ruler are millimeters — there are ten of them in each centimeter. Although the word millimeter sounds like "million," it actually means "thousandth of a meter."
Vocabulary lists containing millimeter
Measurement and Data
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Florida's B.E.S.T. Roots: meter, metr
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Granulation dates to Mesopotamia, but the Etruscans elevated the practice, using granules as small as 0.14 millimeter in diameter, one-seventh the size of those used by Mesopotamians and Egyptians.
From The Wall Street Journal ● Jul. 18, 2026
It all contributes to the most complete officiating picture the World Cup has ever seen, right down to the millimeter.
From The Wall Street Journal ● Jul. 13, 2026
While a single 300 millimeter silicon wafer normally produces a few dozen chips, Cerebras uses the entire wafer for one chip, about the size of a dinner plate.
From Barron's ● May 15, 2026
Meiofauna are tiny invertebrates measuring less than one millimeter long.
From Science Daily ● May 12, 2026
She said, “It doesn’t feel small to me,” and I thought about moving a single grain of sand one millimeter.
From "Extremely Loud and Incredibly Close" by Jonathan Safran Foer
The region, made up of mountains surrounded by a desert steppe, receives just over 100 millimeters of annual rainfall, classifying it as an desert.
From Barron's ● Jun. 15, 2026
A traditional arthroscope measures about 4 millimeters in diameter.
From The Wall Street Journal ● May 26, 2026
But the pace has increased dramatically in recent decades, reaching 3.94 millimeters per year between 2005 and 2023.
From Science Daily ● May 22, 2026
I’ve yet to swoon for a Jane Schoenbrun film, but only because their fixations like “Buffy the Vampire Slayer” fandom are so hyperspecific that they miss me by millimeters.
From Los Angeles Times ● May 11, 2026
His birthday at Alton Towers was canceled, Gavin Coley’s eyes sunk into his skull a few millimeters, and a year later his parents got divorced.
From "Black Swan Green" by David Mitchell
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
