/ Dictionary / Index M mesenchyme: Meaning and Definition of Find definitions for: mes•en•chyme Pronunciation: (mes'eng-kīm, mez'-), [key] — n. Embryol. cells of mesodermal origin that are capable of developing into connective tissues, blood, and lymphatic and blood vessels. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mesenchyme (Thesaurus) mesencephalon mesenteritis 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