The Collaborative International Dictionary of English v.0.48:

Amputate \Am"pu*tate\, v. t. [imp. & p. p. Amputated; p. pr. &
   vb. n. Amputating.] [L. amputatus, p. p. of amputare: amb-
   + putare to prune, putus clean, akin to E. pure. See
   Putative.]
   1. To prune or lop off, as branches or tendrils.
      [1913 Webster]

   2. (Surg.) To cut off (a limb or projecting part of the
      body). --Wiseman.
      [1913 Webster]

WordNet (r) 3.0 (2006):

amputate
    v 1: remove surgically; "amputate limbs" [syn: amputate, cut
         off]

Moby Thesaurus II by Grady Ward, 1.0:

74 Moby Thesaurus words for "amputate":
   abscind, annihilate, ax, ban, bar, bisect, bob, butcher, carve,
   chop, cleave, clip, crop, cull, cut, cut away, cut in two, cut off,
   cut out, dichotomize, dissever, dock, eliminate, enucleate,
   eradicate, except, excise, exclude, extinguish, extirpate, fissure,
   gash, hack, halve, hew, incise, isolate, jigsaw, knock off, lance,
   lop, mutilate, nip, pare, peel, pick out, prune, rend, rive,
   root out, rule out, saw, scissor, set apart, set aside, sever,
   shave, shear, slash, slice, slit, snip, split, stamp out,
   strike off, strip, strip off, sunder, take off, take out, tear,
   truncate, whittle, wipe out