/ Dictionary / Index M mrem: Meaning and Definition of Find definitions for: mrem Pronunciation: [key] millirem; millirems. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. M.R.E. Mr. Fixit Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language