The Collaborative International Dictionary of English v.0.48:

Halve \Hal"ve\ (h[aum]l"ve), n.
   A half. [Obs.] --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Halve \Halve\ (h[aum]v), v. t. [imp. & p. p. Halved
   (h[aum]vd); p. pr. & vb. n. Halving.] [From Half.]
   1. To divide into two equal parts; as, to halve an apple; to
      be or form half of.
      [1913 Webster]

            So far apart their lives are thrown
            From the twin soul that halves their own. --M.
                                                  Arnold.
      [1913 Webster]

   2. (Arch.) To join, as two pieces of timber, by cutting away
      each for half its thickness at the joining place, and
      fitting together.
      [1913 Webster]

   3. Of a hole, match, etc., to reach or play in the same
      number of strokes as an opponent.

WordNet (r) 3.0 (2006):

halve
    v 1: divide by two; divide into halves; "Halve the cake"

Moby Thesaurus II by Grady Ward, 1.0:

61 Moby Thesaurus words for "halve":
   amputate, apportion, ax, be partners in, bifurcate, bisect, branch,
   butcher, by two, carve, chop, cleave, cooperate, cut, cut away,
   cut in two, cut off, dichotomize, dimidiate, dissever, divide,
   divide with, divvy up with, excise, fission, fissure, fork, gash,
   go even stephen, go fifty-fifty, go halvers, go halves, go shares,
   hack, hew, in half, incise, jigsaw, lance, pare, prune, ramify,
   rend, rive, saw, scissor, sever, share, share in, slash, slice,
   slit, snip, split, split in two, split the difference, subdivide,
   sunder, tear, transect, whittle