Dictionary.com
Thesaurus.com

billow cloud

American  

noun

Meteorology.

  1. a cloud consisting of broad, parallel bands oriented perpendicularly to the wind.

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.