/ Dictionary / Index M mission specialist: Meaning and Definition of Find definitions for: mis'sion spe"cialist Pronunciation: [key] the crew member of a space shuttle who is assigned primary responsibility for carrying out operations related to the payload of the shuttle. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. missionize Mission Viejo Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language