asexual

from WordNet (r) 3.0 (2006)

asexual
    adj 1: not having or involving sex; "an asexual spore"; "asexual
           reproduction" [syn: {asexual}, {nonsexual}] [ant:
           {sexual}]

from The Collaborative International Dictionary of English v.0.48

Asexual \A*sex"u*al\ (?; 135), a. [Pref. a- not + sexual.]
   1. (Biol.) Having no distinct sex; without sexual action; as,
      asexual reproduction. See {Fission} and {Gemmation}.
      [1913 Webster]

   2. not involving sexual activity or sexual attraction; as, an
      asexual friendship.
      [PJC]