ami·no·pep·ti·dase \ ̷ ̷ˌ ̷ ̷ ̷ ̷ˈpeptəˌdās, | ̷ ̷ ̷ ̷ ̷ ̷ˈ-\noun (-s) Etymology:amin- + peptide + -ase : an enzyme (as an enzyme found in the duodenum) that hydrolyzes peptides, especially polypeptides, by splitting off the amino acids containing free amino groups