The Collaborative International Dictionary of English v.0.48:

Delimit \De*lim"it\, v. t. [L. delimitare: cf. F. d['e]limiter.]
   To fix the limits of; to demarcate; to bound.
   [1913 Webster]

WordNet (r) 3.0 (2006):

delimit
    v 1: determine the essential quality of [syn: specify,
         define, delineate, delimit, delimitate]
    2: be opposite to; of angles and sides, in geometry [syn:
       subtend, delimit]
    3: set, mark, or draw the boundaries of something [syn:
       demarcate, delimit, delimitate]

Moby Thesaurus II by Grady Ward, 1.0:

84 Moby Thesaurus words for "delimit":
   bar, blaze, blaze a trail, blemish, blotch, bound, brand, chalk,
   chalk up, check, check off, cicatrize, circle in, circumscribe,
   confine, dapple, dash, decide, define, delimitate, demarcate,
   determine, discolor, dot, enclose, engrave, fix, fleck, freckle,
   gash, hatch, impress, imprint, lay off, limit, line, make a mark,
   mark, mark boundaries, mark off, mark out, mark the periphery,
   measure, mottle, nick, notch, pencil, pepper, point, prick, print,
   punch, punctuate, puncture, restrict, riddle, rope off, scar,
   scarify, score, scotch, scratch, seal, seam, set the limit,
   specify, speck, speckle, splotch, spot, stain, stake out, stamp,
   stigmatize, streak, striate, stripe, surround, tattoo, tick,
   tick off, trace, underline, underscore