/ Dictionary / Index M mummy bag: Meaning and Definition of Find definitions for: mum'my bag" Pronunciation: [key] a snug-fitting sleeping bag tapered from the shoulders to the feet, enclosing both the body and head except for a small opening for the face. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mummy mump Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language