The Collaborative International Dictionary of English v.0.48:

Coleoptera \Co`le*op"te*ra\, n. pl. [NL., fr. Gr. ?
   sheath-winged; ? sheath + ? wing.] (Zool.)
   An order of insects having the anterior pair of wings
   (elytra) hard and horny, and serving as coverings for the
   posterior pair, which are membranous, and folded transversely
   under the others when not in use. The mouth parts form two
   pairs of jaws (mandibles and maxill[ae]) adapted for chewing.
   Most of the Coleoptera are known as beetles and weevils.
   [1913 Webster] Coleopteral

WordNet (r) 3.0 (2006):

Coleoptera
    n 1: beetles [syn: Coleoptera, order Coleoptera]