ˈpepsə̇n noun
( -s )
Etymology: German, from Greek pepsis digestion (from peptein, pessein to cook, digest) + German -in
1. : a crystallizable proteinase that in an acid medium digests most proteins to polypeptides (as by dissolving coagulated egg albumin or causing casein to precipitate from skim milk), that is secreted by glands in the mucous membrane of the stomach of higher animals, and that in combination with dilute hydrochloric acid is the chief active principle of gastric juice
2. : a preparation containing pepsin obtained as a powder or scales from the stomach especially of the hog and used chiefly as a digestant, in making peptones, and in digesting gelatin for the recovery of silver from photographic film