The Collaborative International Dictionary of English v.0.48:

lagomorph \lag"o*morph\, n. (Zool.)
   One of the Lagomorpha.
   [1913 Webster]

WordNet (r) 3.0 (2006):

lagomorph
    n 1: relative large gnawing animals; distinguished from rodents
         by having two pairs of upper incisors specialized for
         gnawing [syn: lagomorph, gnawing mammal]