/ Dictionary / Index M mesorectum: Meaning and Definition of Find definitions for: mes•o•rec•tum Pronunciation: (mez"u-rek'tum, mes"-, mē"zu-, -su-), [key] — pl. -tums, -ta the mesentery of the rectum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Mesopotamia mesorrhine Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language