/ Dictionary / Index M mesembryanthemum: Meaning and Definition of Find definitions for: me•sem•bry•an•the•mum Pronunciation: (mu-zem"brē-an'thu-mum), [key] — n. any of various chiefly Old World plants of the genus Mesembryanthemum, having thick, fleshy leaves and often showy flowers. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mesembryanthemum (Thesaurus) meseems mesencephalon Related Content Daily Word Quiz: simian Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language