/ Dictionary / Index P peritonitis: Meaning and Definition of Find definitions for: per•i•to•ni•tis Pronunciation: (per"i-tn-ī'tis), [key] — n. Pathol. inflammation of the peritoneum, often accompanied by pain and tenderness in the abdomen, vomiting, constipation, and moderate fever. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: peritonitis (Thesaurus) peritoneum Peritrate Related Content Daily Word Quiz: penurious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language