Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

See What's Trending Now See More Trending Words

water vapor

noun

Definition of water vapor

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

See water vapor defined for kids

Explore M-W

watercolor-squares
We're Down With You Being—or Your Being?—a Square
steve-bannon
Trending: Bannon: One of Us is Going to be a 'Hegemon'
video-title-words-of-the-year-1066
Words of the Year: 1066
time-traveler-quiz-which-word-came-first
Time Traveler Quiz: Which Word Came First?

First Known Use of water vapor

15th century

Medical Dictionary

water vapor

noun

Medical Definition of water vapor

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

Seen and Heard

What made you want to look up water vapor? Please tell us where you read or heard it (including the quote, if possible).

show hide

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

oppugn

play

to fight against or to call in question

Get Word of the Day daily email!

TRENDING NOW

  1. hegemon "Something having dominant influence over others"

  2. repugnant Trump clarifies his position on racism

  3. white nationalist, white supremacist Trending in 2017

  4. bereft "Lacking something needed, wanted, or expected"

  5. impanel "To choose people to serve on a jury"

SEE ALL

BROWSE DICTIONARY

water vapor

Test Your Vocabulary

Time Traveler Quiz: Which Word Came First?

  • time-traveler-quiz-which-word-came-first
  • Which came first?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play

watercolor-squares
We're Down With You Being—or Your Being?—a Square

It's about (you? your?) having your say.

image1489982902
Devilish Words

Don't blame a word use error on the devil.

alt-599492594f435
How 'Wonderful' Lost Its Sense of Wonder

A case of semantic bleaching

dog-covering-face
Don't Let Reading This Be Another 'Coulda' 'Shoulda' 'Woulda'

PSA: They're three separate words.

Ask the Editors

video-title-words-of-the-year-1066
Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

payday
How Often Is 'Biweekly'?

Don't get us started on 'bimonthly'

video-irregardless-grammar-peeve-blend-of-the-synonyms-irrespective-and-regardless
Irregardless

It is in fact a real word (but that doesn't mean you should use it).

video-moose-goose-weird-plurals
Weird Plurals

One goose, two geese. One moose, two... moose. What's up with that?

Word Games

time-traveler-quiz-which-word-came-first
Time Traveler Quiz: Which Word Came First?

Which word entered the English language first?

Take the quiz
name-more-food
Name More Food!

Test your knowledge of food vocabulary!

Take the quiz
Spell It
Spell It

Can you spell these 10 commonly misspelled words?

Take the quiz
Word Winder's CrossWinder
Word Winder's CrossWinder

A game of winding words.

Play the game