/ Dictionary / Index E encephalitis: Meaning and Definition of Find definitions for: en•ceph•a•li•tis Pronunciation: (en-sef"u-lī'tis), [key] — n. Pathol. inflammation of the substance of the brain. Also calleda form of this condition, caused by a filterable virus and characterized by apathy and abnormal sleepiness; sleeping sickness. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: encephalitis (Thesaurus) encephalic encephalo- Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language