To save this word, you'll need to log in.
Definition of billow cloud
: a long narrow cloud or usually a series of such clouds roughly parallel to each other caused by the flow of one layer of air over another producing waves at their interface the relatively cold crests of which are cloud-capped and their relatively warm troughs clear when the humidity is just right
Comments on billow cloud
What made you want to look up billow cloud? Please tell us where you read or heard it (including the quote, if possible).
Test Your Vocabulary
Words for Summer: A Quiz
- Which of the following words means “of or relating to summer”?
Can you spell these 10 commonly misspelled words?
TAKE THE QUIZ
Test Your Knowledge - and learn some interesting things along the way.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
- Words for Summer: A Quiz
Test your knowledge of words related to the season of longer days and vacations.
Take the quiz - A More Exception(al) Quiz
Which of these things doesn't belong?
Take the quiz - Spell It
Can you spell these 10 commonly misspelled words?
Take the quiz - Syn City
Build a city of skyscrapers—one synonym at a time.
Play the game
Share billow cloud