The Collaborative International Dictionary of English v.0.48:

Viperoidea \Vi`per*oi"de*a\, Viperoides \Vi`per*oi"des\, n. pl.
   [NL. See Viper, and -oid.] (Zool.)
   A division of serpents which includes the true vipers of the
   Old World and the rattlesnakes and moccasin snakes of
   America; -- called also Viperina.
   [1913 Webster]