/ Dictionary / Index C Cerberus: Meaning and Definition of Find definitions for: Cer•ber•us Pronunciation: (sûr'bur-us), [key] — pl. -ber•us•es, -ber•i a dog, usually represented as having three heads, that guarded the entrance of the infernal regions. a formidable and often surly keeper or guard. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cerberus (Thesaurus) ceratosaur cercaria Related Content Daily Word Quiz: lunar Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language