E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Cerberus.
A grim, watchful keeper, house-porter, guardian, etc. Cerberus, according to Roman mythology, is the three-headed dog that keeps the entrance of the infernal regions. Herculës dragged the monster to earth, and then let him go again. (See SOP.)
1
Orpheus (2 syl.) lulled Cerberus to sleep with his lyre; and the Sibyl who conducted Ænas through the Inferno, also threw the dog into a profound sleep with a cake seasoned with poppies and honey.
2
The origin of the fable of Cerberus is from the custom of the ancient Egyptians of guarding graves with dogs.
3
The exquisite cameo by Dioscordês, in the possession of the King of Prussia, and the painting of Hercules and Cerberus, in the Farnésé Gallery of Rome, are of world-wide renown.