The Collaborative International Dictionary of English v.0.48:

Anura \A*nu"ra\ ([.a]*n[=u]"r[.a]), n. pl. [NL., fr. Gr. 'an
   priv. + o'yra` a tail.] (Zool.)
   One of the orders of amphibians characterized by the absence
   of a tail, as the frogs and toads. [Written also anoura.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

Anura
    n 1: frogs, toads, tree toads [syn: Salientia, order
         Salientia, Anura, order Anura, Batrachia, order
         Batrachia]