/ Dictionary / Index M moon shell: Meaning and Definition of Find definitions for: moon' shell" Pronunciation: [key] any marine gastropod of the family Naticidae, having a rounded, short-spired, smooth shell. the shell itself. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: moonshell (Thesaurus) moonshee moonshine 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