Source : Webster's Revised Unabridged Dictionary (1913)

Deformity \De*form"i*ty\, n.; pl. {Deformities}. [L. deformitas,
   fr. deformis: cf. OF. deformet['e], deformit['e], F.
   difformit['e]. See {Deform}, v. & a., and cf. {Disformity}.]
   1. The state of being deformed; want of proper form or
      symmetry; any unnatural form or shape; distortion;
      irregularity of shape or features; ugliness.

            To make an envious mountain on my back, Where sits
            deformity to mock my body.            --Shak.

   2. Anything that destroys beauty, grace, or propriety;
      irregularity; absurdity; gross deviation from order or the
      established laws of propriety; as, deformity in an
      edifice; deformity of character.

            Confounded, that her Maker's eyes Should look so
            near upon her foul deformities.       --Milton.

Source : WordNet®

deformity
     n 1: an affliction in which some part of the body is misshapen or
          malformed [syn: {malformation}, {misshapenness}]
     2: an appearance that has been spoiled or is misshapen; "there
        were distinguishing disfigurements on the suspect's back";
        "suffering from facial disfiguration" [syn: {disfigurement},
         {disfiguration}]