/ Dictionary / Index D duodenum: Meaning and Definition of Find definitions for: du•o•de•num Pronunciation: (d"u-dē'num, dy"-&wdspcd-od'n-um, dy-), [key] — pl. du•o•de•na du•o•de•nums. the first portion of the small intestine, from the stomach to the jejunum. See diag. under Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: duodenum (Thesaurus) duodenojejunostomy duologue Related Content Daily Word Quiz: crutiny Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language