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
One method for producing millimeter waves relies on a device known as a microcomb.
From Science Daily ● Aug. 24, 2026
The crystal measures only about a millimeter in size, making ordinary methods of collecting sunlight impractical.
From Science Daily ● Aug. 8, 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
Winston dared not turn his head even by a millimeter, but sometimes her livid, gasping face came within the angle of his vision.
From "1984" by George Orwell
Sea-level rise is measured in millimeters, so tiny drifts in the reference frame prevent accurate calculations of coastal risk.
From The Wall Street Journal ● Aug. 7, 2026
That rate is nearly three times the coastline-weighted global average of 2.1 millimeters per year, which represents the mean relative increase recorded along coastlines worldwide.
From Science Daily ● Aug. 3, 2026
Their population-weighted coastal averages range from roughly 7 to 10 millimeters per year.
From Science Daily ● Aug. 3, 2026
Clarke’s team has spent the last two years sweating grams, watts, millimeters and pennies from every component, system or process, over and over.
From The Wall Street Journal ● Jun. 20, 2026
That’s when I saw an Irukandji, just millimeters from my skin.
From "The Thing About Jellyfish" by Ali Benjamin
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.
