millimeter
Americannoun
-
millimeters
plural
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:
In a milieu where every fold and crease, every millimeter of negative draft or change of curvature, adds cost, the S5 saves.
From The Wall Street Journal ● Oct. 24, 2026
They grow about a centimeter or two a year and by sampling cores at the millimeter scale, the team was able to develop windows of monthly temperature records scattered across the past millennium.
From Barron's ● Aug. 27, 2026
Earlier research demonstrated that microcombs could produce a single precise millimeter wave frequency.
From Science Daily ● Aug. 24, 2026
The other scientist insisted “I don’t believe a half of a millimeter really matters so much.”
From The Wall Street Journal ● Aug. 24, 2026
He came down with a nasty gash a millimeter above his right eye.
From "Seabiscuit: An American Legend" by Laura Hillenbrand
Its mirror was ground and polished with extraordinary precision—to the wrong shape, because a lens in the test device sat 1.3 millimeters out of place.
From The Wall Street Journal ● Nov. 6, 2026
They also had to be in direct contact -- a few millimeters apart, and nothing significant happened.
From Barron's ● Oct. 14, 2026
That enormous concentration of water pulls Earth's center of mass 2.2 millimeters toward South America.
From Science Daily ● Oct. 7, 2026
As those materials move, Earth's center of mass circles around its geometric center by as much as several millimeters.
From Science Daily ● Oct. 7, 2026
A typical paramecium, for instance, is about two microns wide, 0.002 millimeters, which is really very small.
From "A Short History of Nearly Everything" by Bill Bryson
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Get a wordDefinitions 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.
