/ Dictionary / Index S secretin: Meaning and Definition of Find definitions for: se•cre•tin Pronunciation: (si-krē'tin), [key] — n. Biochem. a polypeptide hormone, produced in the small intestine, that activates the pancreas to secrete pancreatic juice. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: secretin (Thesaurus) secrete secretion Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language