/ Dictionary / Index C cumulo-: Meaning and Definition of Find definitions for: cumulo- Pronunciation: [key] a combining form representingin compound words. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cumuliform cumulonimbus Related Content Daily Word Quiz: lyceum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language