The Collaborative International Dictionary of English v.0.48:

lepidopteran \lepidopteran\ a.
   Same as lepidopterous.
   [PJC]

The Collaborative International Dictionary of English v.0.48:

lepidopteran \lepidopteran\ n.
   An insect that in the adult state has four wings more or less
   covered with tiny scales; a lepidopterous insect.

   Syn: lepidopterous insect, lepidopteron.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

lepidopteran
    n 1: insect that in the adult state has four wings more or less
         covered with tiny scales [syn: lepidopterous insect,
         lepidopteron, lepidopteran]