The Collaborative International Dictionary of English v.0.48:

Lagomorpha \Lag`o*mor"pha\ (l[a^]g`[-o]*m[^o]r"f[.a]), prop. n.
   pl. [NL., fr. Gr. lagw`s a hare + morfh` form.] (Zool.)
   an order of rodent-like mammals, comprising the hares,
   rabbits, and pikas. They have four incisors in the upper jaw.
   Called also Duplicidentata. They were formerly classified
   together with the rodents, but the Rodentia and
   Lagomorpha are now classed as separate orders.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

Lagomorpha
    n 1: rabbits; hares; pikas; formerly considered the suborder
         Duplicidentata of the order Rodentia [syn: Lagomorpha,
         order Lagomorpha]