Entry 2 senses · 2 variants Webster, 1913 lepidopteran · IPA a. n. 01 a. Same as lepidopterous. 1. Same as lepidopterous. See: lepidopterous 02 n. An insect that in the adult state has four wings more or less covered with tiny scales; a lepidopterous insect. 1. An insect that in the adult state has four wings more or less covered with tiny scales; a lepidopterous insect. Syn. lepidopterous insect, lepidopteron.