/ Dictionary / Index P phrenitis: Meaning and Definition of Find definitions for: phre•ni•tis Pronunciation: (fri-nī'tis), [key] — n. Pathol. inflammation of the brain; encephalitis. delirium; frenzy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: phrenitis (Thesaurus) phrenic phreno- Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language