Source : Webster's Revised Unabridged Dictionary (1913)

Apterous \Ap"ter*ous\, a.
   1. (Zo["o]l.) Destitute of wings; apteral; as, apterous
      insects.

   2. (Bot.) Destitute of winglike membranous expansions, as a
      stem or petiole; -- opposed to {alate}.

Source : WordNet®

apterous
     adj : (of insects) without wings [syn: {apteral}]