/ Dictionary / Index M mCi: Meaning and Definition of Find definitions for: mCi Pronunciation: [key] millicurie; millicuries. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. MChin McIntire Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language