Source : Webster's Revised Unabridged Dictionary (1913)

Deform \De*form"\, a. [L. deformis; de- + forma form: cf. OF.
   deforme, F. difforme. Cf. {Difform}.]
   Deformed; misshapen; shapeless; horrid. [Obs.]

         Sight so deform what heart of rock could long Dry-eyed
         behold?                                  --Milton.

Deform \De*form"\, v. t. [imp. & p. p. {Deformed}; p. pr. & vb.
   n. {Deforming}.] [L. deformare; de- + formare to form, shape,
   fr. forma: cf. F. d['e]former. See {Form}.]
   1. To spoil the form of; to mar in form; to misshape; to
      disfigure.

            Deformed, unfinished, sent before my time Into this
            breathing world.                      --Shak.

   2. To render displeasing; to deprive of comeliness, grace, or
      perfection; to dishonor.

            Above those passions that this world deform.
                                                  --Thomson.

Source : WordNet®

deform
     v 1: make formless; "the heat deformed the plastic sculpture"
          [ant: {form}]
     2: twist and press out of shape [syn: {contort}, {distort}, {wring}]
     3: cause (a plastic object) to assume a crooked or angular
        form; "bend the rod"; "twist the dough into a braid"; "the
        strong man could turn an iron bar" [syn: {flex}, {bend}, {twist},
         {turn}] [ant: {unbend}]
     4: become misshapen; "The sidewalk deformed during the
        earthquake"
     5: alter the shape of (something) by stress; "His body was
        deformed by leprosy" [syn: {distort}, {strain}]
     6: assume a different shape or form [syn: {change shape}, {change
        form}]