a protein-splitting enzyme from the juice of unripe papaya, used as a digestive aid, as a meat tenderizer, in pharmacy, etc.
Origin of papainpapa(ya) + -in
An enzyme obtained from the unripe fruit of the papaya that catalyzes the lysis of proteins, used especially as a meat tenderizer and digestive aid and formerly in medicine as a topical treatment for wounds.
Origin of papainpapa(ya) -in
Circa 19th century, from papaya +"Ž -in.