/ Dictionary / Index M meristem: Meaning and Definition of Find definitions for: mer•i•stem Pronunciation: (mer'u-stem"), [key] — n. Bot. embryonic tissue in plants; undifferentiated, growing, actively dividing cells. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: meristem (Thesaurus) merisis meristematic 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