kilometer

noun

ki·​lo·​me·​ter kə-ˈlä-mə-tər How to pronounce kilometer (audio)
ki-;
ˈki-lə-ˌmē-tər How to pronounce kilometer (audio)
ˈkē-lə-
: a metric unit of length equal to 1000 meters see Metric System Table
How do you pronounce kilometer?: Usage Guide

In North American speech kilometer is most often pronounced with primary stress on the second syllable. This pronunciation is also heard frequently in British speech. Those who object to second syllable stress say that the first syllable should be stressed in accord with the stress patterns of centimeter, millimeter, etc. However, the pronunciation of kilometer does not parallel that of other metric compounds. From 1828 to 1841 Noah Webster indicated only second syllable stress, and his successor added a first syllable stress variant in the first Merriam-Webster dictionary of 1847. Thus, both pronunciations are venerable. Most scientists use second syllable stress, although first syllable stress seems to occur with a higher rate of frequency among scientists than among nonscientists.

Did you know?

A kilometer is equal to about 62/100 of a mile, and a mile is equal to about 1.61 kilometers. The U.S. has been slow to adopt metric measures, which are used almost everywhere else in the world. Though our car speedometers are often marked in both miles and kilometers, the U.S. and Great Britain are practically the only developed nations that still show miles rather than kilometers on their road signs. But even in the U.S., footraces are usually measured in meters or kilometers, like the Olympic races. Runners normally abbreviate kilometer to K: "a 5K race" (3.1 miles), "the 10K run" (6.2 miles), and so on.

Examples of kilometer in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The nuclear complex there, about 250 kilometers (150 miles) south of the capital Tehran, is considered Iran’s largest uranium enrichment facility. Mostafa Salem, CNN Money, 13 June 2025 The tower, in Saudi Arabia, would be the first to reach 2 kilometers (1.2 miles), or 6,562 feet, in height—more than four times as tall as the Empire State Building and overtaking both the Burj Khalifa and the upcoming Jeddah Tower, which is also under construction in the country. Theo Burman, MSNBC Newsweek, 12 June 2025 These trials have varied in terms of distance—ranging from a few hundred meters to several tens of kilometers—and have focused on performance metrics such as composable secret key rates, which, so far, typically remain below 500 kbps. Vibhu Sharma, Forbes.com, 11 June 2025 That future impact location could potentially be narrowed down to within a hundred kilometers. IEEE Spectrum, 11 June 2025 See All Example Sentences for kilometer

Word History

Etymology

French kilomètre, from kilo- + mètre meter

First Known Use

1810, in the meaning defined above

Time Traveler
The first known use of kilometer was in 1810

Browse Nearby Words

Cite this Entry

“Kilometer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/kilometer. Accessed 17 Jun. 2025.

Kids Definition

kilometer

noun
ki·​lo·​me·​ter kə-ˈläm-ət-ər How to pronounce kilometer (audio) kil-ˈäm- How to pronounce kilometer (audio)
ˈkil-ə-ˌmēt-ər
: a metric unit of length equal to 1000 meters see metric system

Medical Definition

kilometer

noun
ki·​lo·​me·​ter
variants or chiefly British kilometre
: 1000 meters

More from Merriam-Webster on kilometer

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