/ Dictionary / Index M mushroom cloud: Meaning and Definition of Find definitions for: mush'room cloud" Pronunciation: [key] mushroom (def. 4). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mushroom anchor mushroom slab construction Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language