The Collaborative International Dictionary of English v.0.48:

Truncate \Trun"cate\, a. [L. truncatus, p. p. ]
   Appearing as if cut off at the tip; as, a truncate leaf or
   feather.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Truncate \Trun"cate\, v. t. [imp. & p. p. Truncated; p. pr. &
   vb. n. Truncating.] [L. truncatus, p. p. of truncare to cut
   off, mutilate, fr. truncus maimed, mutilated, cut short. See
   Trunk.]
   To cut off; to lop; to maim.
   [1913 Webster]

WordNet (r) 3.0 (2006):

truncate
    adj 1: terminating abruptly by having or as if having an end or
           point cut off; "a truncate leaf"; "truncated volcanic
           mountains"; "a truncated pyramid" [syn: truncate,
           truncated]
    v 1: replace a corner by a plane
    2: approximate by ignoring all terms beyond a chosen one;
       "truncate a series"
    3: make shorter as if by cutting off; "truncate a word";
       "Erosion has truncated the ridges of the mountains" [syn:
       truncate, cut short]

Moby Thesaurus II by Grady Ward, 1.0:

85 Moby Thesaurus words for "truncate":
   abbreviate, abridge, abscind, abstract, amputate, annihilate, ban,
   bar, blemish, bob, boil down, capsulize, clip, compress, condense,
   contract, crop, cull, curtail, cut, cut away, cut back, cut down,
   cut off, cut off short, cut out, cut short, deface, deform,
   disfigure, disproportion, dock, elide, eliminate, enucleate,
   epitomize, eradicate, except, excise, exclude, extinguish,
   extirpate, foreshorten, isolate, knock off, lop, mar, misshape,
   mow, mutilate, nip, pare, peel, pick out, poll, pollard, prune,
   reap, recap, recapitulate, reduce, retrench, root out, rule out,
   set apart, set aside, shave, shear, shorten, snub, stamp out,
   strike off, strip, strip off, stunt, sum up, summarize, synopsize,
   take in, take off, take out, telescope, top, trim, wipe out