or pep·sine

[ pep-sin ]

  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.

Origin of pepsin

1835–45; <Greek péps(is) digestion (pep-, base of péptein to digest + -sis-sis) + -in2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use pepsin in a sentence

British Dictionary definitions for pepsin



/ (ˈpɛpsɪn) /

  1. a proteolytic enzyme produced in the stomach in the inactive form pepsinogen, which, when activated by acid, splits proteins into peptones

Origin of pepsin

C19: via German from Greek pepsis, from peptein to digest

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for pepsin


[ pĕpsĭn ]

  1. Any of various digestive enzymes found in vertebrate animals that catalyze the hydrolysis of proteins to peptides.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.