/ Dictionary / Index M mysid: Meaning and Definition of Find definitions for: my•sid Pronunciation: (mī'sid), [key] — n. any member of the malacostracan order Mysidacea, the opossum shrimps, esp. of the genus Mysis. —adj. of or pertaining to such shrimps. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Mysia Mysliveček Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language