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:
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
A specialized antenna can then convert those optical frequencies into millimeter waves.
From Science Daily ● Aug. 24, 2026
Earlier research demonstrated that microcombs could produce a single precise millimeter wave frequency.
From Science Daily ● Aug. 24, 2026
"That has paid off really well for us because there are a lot of people out there that are seeking that 70 millimeter presentation."
From Barron's ● Jul. 26, 2026
Desperate to see what was happening and why, Harry opened his eyes by a millimeter.
From "Harry Potter and the Deathly Hallows" by J.K. Rowling
It measured an impressive 86.6 millimeters, or approximately 3.4 inches, excluding its tail, claws, and antennae.
From Science Daily ● Oct. 16, 2026
They also had to be in direct contact -- a few millimeters apart, and nothing significant happened.
From Barron's ● Oct. 14, 2026
Each colony was positioned about 5 millimeters from its nearest neighbor.
From Science Daily ● Sep. 4, 2026
In July, just 2 millimeters of rain fell in East Anglia, drying out fields and shriveling vegetables in one of the U.K.’s breadbaskets.
From The Wall Street Journal ● Aug. 31, 2026
That’s when I saw an Irukandji, just millimeters from my skin.
From "The Thing About Jellyfish" by Ali Benjamin
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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.
