/ Dictionary / Index M mantle plume: Meaning and Definition of Find definitions for: man'tle plume' Pronunciation: [key] plume (def. 10). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mantlepiece mantle rock 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