kilometer
Americannoun
-
kilometers
plural
Pronunciation
The usual pronunciation for units of measurement starting with kilo-, as kilocalorie, kiloliter, and kilohertz, as well as for units of length ending in the base word meter, as centimeter, hectometer, and millimeter, gives primary stress to the first syllable and secondary to the third. It would seem logical for kilometer to follow this pattern, and in fact the pronunciation has been used since the early 1800's. A second pronunciation: , with stress on the second syllable only, was first recorded in America before 1830. Although often criticized on the basis of analogy, this pronunciation has persisted in American English, increasing in frequency, and has gained popularity in British English as well. It is reinforced by words for instruments (rather than units) of measurement ending in -meter, as thermometer, barometer, and speedometer, having stress on the -om syllable. Both pronunciations are used by educated speakers, including members of the scientific community.
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of kilometer
First recorded in 1800–10; from French kilomètre; see origin at kilo-, meter 1
Explanation
A kilometer is a unit of metric measurement that's about 2/3 as long as a mile. If you sign up for a five kilometer race, you'll be running a course that's a little over three miles long. Most countries around the world measure geographical distance using kilometers rather than miles — the exceptions are the U.S. and the U.K. The word means "one thousand meters," from Greek roots khilioi, "thousand," and metron, "measure." As you might guess, there are a thousand meters in a single kilometer. If you drive from the U.S. across the Canadian border, expect to see speed limit signs change from miles per hour to kilometers per hour.
Vocabulary lists containing kilometer
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 will be able to greet the pontiff as the Popemobile travels one kilometer to get to the home.
From Barron's ● Nov. 2, 2026
If that doesn’t sound hard enough, participants have to run a kilometer before each station.
From The Wall Street Journal ● Sep. 18, 2026
A net kick of about 1 kilometer per second could disrupt the orbit of a loosely bound stellar pair, causing the two stars to separate.
From Science Daily ● Jul. 21, 2026
That all spells exciting times for sleepy, regulated natural monopolies that control the last kilometer to the customer.
From Barron's ● May 27, 2026
“Yeah, there’s a vein of iron about half a kilometer that way. But nothing between here and there.”
From "Uglies" by Scott Westerfeld
The whole genus is known from just seven specimens gathered over about 65 years, scattered across more than 2,500 kilometers of coastline, and nothing has been collected in nearly two decades.
From Science Daily ● Oct. 30, 2026
The Su‑35, he noted, is equipped for both air‑to‑air and air‑to‑ground combat, with the ability to detect and neutralize incoming cruise missiles at distances of up to 200 kilometers.
From BBC ● Oct. 29, 2026
It remains unknown how he got to Argentina from Brasilia, more than 1,500 kilometers away.
From Barron's ● Oct. 28, 2026
"The future projections similarly end up being lower than previous estimates, by about a million square kilometers."
From Science Daily ● Oct. 26, 2026
So, instead of resting, he hurried north toward Makeni, a city many kilometers away, where he thought it might be safe.
From "Taking Flight: From War Orphan to Star Ballerina" by Michaela DePrince
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