The Collaborative International Dictionary of English v.0.48:

Orthoptera \Or*thop"te*ra\, prop. n. pl. [NL., fr. Gr. 'orqo`s
   straight + ? feather, wing.] (Zool.)
   An order of mandibulate insects including grasshoppers,
   locusts, cockroaches, mantids, crickets, katydids, etc. See
   Illust. under Insect.
   [1913 Webster]

   Note: The anterior wings are usually thickened and protect
         the membranous posterior wings, which are larger and
         fold longitudinally like a fan. They also have chewing
         mouth parts. The Orthoptera undergo no metamorphosis.
         [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

Orthoptera
    n 1: grasshoppers and locusts; crickets [syn: Orthoptera,
         order Orthoptera]