%cerberus%

n. [ L. Cerberus (in sense 1), gr. &unr_;. ] [ 1913 Webster ]

1. (Class. Myth.) A monster, in the shape of a three-headed dog, guarding the entrance into the infernal regions, Hence: Any vigilant custodian or guardian, esp. if surly. [ 1913 Webster ]

2. (Zool.) A genus of East Indian serpents, allied to the pythons; the bokadam. [ 1913 Webster ]