/ Dictionary / Index G gastrin: Meaning and Definition of Find definitions for: gas•trin Pronunciation: (gas'trin), [key] — n. a hormone that stimulates the secretion of gastric juice. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: gastrin (Thesaurus) gastric ulcer gastritis Related Content Daily Word Quiz: pugilist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language