/pep"sin/ , n. Biochem.
1. an enzyme, produced in the stomach, that in the presence of hydrochloric acid splits proteins into proteoses and peptones.
2. a commercial form of this substance, obtained from the stomachs of hogs, used as a digestive, as a ferment in the manufacture of cheese, etc.
Also, pepsine .
[ 1835-45; péps ( is ) digestion ( pep-, base of péptein to digest + -sis -SIS) + -IN 2 ]