water vapor

noun

: water in a vaporous form especially when below boiling temperature and diffused (as in the atmosphere)

Examples of water vapor 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 National Oceanic and Atmospheric Administration (NOAA) describes atmospheric rivers as long, narrow bands of moisture in the sky that transport most of the water vapor outside the tropics. Joe Edwards, MSNBC Newsweek, 16 Oct. 2025 Once exposed to sunlight, these clumps are warmed up and act like miniature steam vents in space, releasing water vapor even though the comet itself remains too cold for its surface ice to sublimate directly, the researchers say. Sharmila Kuthunur, Space.com, 10 Oct. 2025 The Puerto Rican scientist researches tropical atmospheric systems, with a focus on how water vapor and humidity play a key role in shaping the weather there. Emily Kwong, NPR, 10 Oct. 2025 But two low-pressure systems, one on either side of India, may have contributed to the event by funneling high levels of water vapor from the Bay of Bengal into the Everest region. Stephanie Pappas, Scientific American, 8 Oct. 2025 See All Example Sentences for water vapor

Word History

First Known Use

15th century, in the meaning defined above

Time Traveler
The first known use of water vapor was in the 15th century

Browse Nearby Words

Cite this Entry

“Water vapor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/water%20vapor. Accessed 23 Oct. 2025.

Kids Definition

water vapor

noun
: water in a gaseous form especially when below boiling temperature and spread through the atmosphere

Medical Definition

water vapor

noun
: water in a vaporous form especially when below boiling temperature and diffused (as in the atmosphere)
Last Updated: - Updated example sentences
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