The Collaborative International Dictionary of English v.0.48:

Ophiophagus \O`phi*oph"a*gus\, n. [NL. See Ophiophagous.]
   (Zool.)
   A genus of venomous East Indian snakes, which feed on other
   snakes. Ophiophagus elaps is said to be the largest and
   most deadly of poisonous snakes.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Ophiophagus
    n 1: king cobra [syn: Ophiophagus, genus Ophiophagus]