Source : Webster's Revised Unabridged Dictionary (1913)

Aberrant \Ab*er"rant\, a. [L. aberrans, -rantis, p. pr. of
   aberrare. See {Aberr}.]
   1. Wandering; straying from the right way.

   2. (Biol.) Deviating from the ordinary or natural type;
      exceptional; abnormal.

            The more aberrant any form is, the greater must have
            been the number of connecting forms which, on my
            theory, have been exterminated.       --Darwin.

Source : WordNet®

aberrant
     adj : markedly different from an accepted norm; "aberrent
           behavior"; "deviant ideas" [syn: {deviant}]
     n : one whose behavior departs substantially from the norm of a
         group