cerberus Meaning, Definition & Usage

  1. noun (Greek mythology) the three-headed dog guarding the entrance to Hades; son of Typhon
    hellhound.

WordNet

Cer"be*rus noun
Etymology
L. Cerberus (in sense 1), gr. .
Definitions
  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.
  2. (Zoöl.) A genus of East Indian serpents, allied to the pythons; the bokadam.

Webster 1913