The Collaborative International Dictionary of English v.0.48:

Hurdle \Hur"dle\, v. t. [imp. & p. p. Hurdleed; p. pr. & vb.
   n. Hurdleing.]
   To hedge, cover, make, or inclose with hurdles. --Milton.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hurdle \Hur"dle\, n. [OE. hurdel, hirdel, AS. hyrdel; akin to D.
   horde, OHG. hurt, G. h["u]rde a hurdle, fold, pen, Icel. hur?
   door, Goth. ha['u]rds, L. cratis wickerwork, hurdle, Gr. ?,
   Skr. k?t to spin, c?t to bind, connect. [root]16. Cf.
   Crate, Grate, n.]
   1. A movable frame of wattled twigs, osiers, or withes and
      stakes, or sometimes of iron, used for inclosing land, for
      folding sheep and cattle, for gates, etc.; also, in
      fortification, used as revetments, and for other purposes.
      [1913 Webster]

   2. In England, a sled or crate on which criminals were
      formerly drawn to the place of execution. --Bacon.
      [1913 Webster]

   3. An artificial barrier, variously constructed, over which
      men or horses leap in a race.
      [1913 Webster]

   Hurdle race, a race in which artificial barriers in the
      form of hurdles, fences, etc., must be leaped.
      [1913 Webster]

WordNet (r) 3.0 (2006):

hurdle
    n 1: a light movable barrier that competitors must leap over in
         certain races
    2: an obstacle that you are expected to overcome; "the last
       hurdle before graduation"
    3: the act of jumping over an obstacle [syn: vault, hurdle]
    v 1: jump a hurdle

Moby Thesaurus II by Grady Ward, 1.0:

99 Moby Thesaurus words for "hurdle":
   Highland fling, and jump, bar, barrier, block, blockade,
   bottleneck, bounce, bound, broad jump, buck, buckjump, capriole,
   catch, check, clear, complication, conquer, cordon, curtain,
   curvet, demivolt, determent, deterrent, difficulty, down, drawback,
   flying jump, galliard, gelandesprung, grand jete, hamper, handicap,
   handspring, hang-up, hazard, high jump, hindrance, hippety-hop,
   hitch, hop, impediment, interference, jete, jig, joker, jump,
   jump over, jump shot, jump turn, jump-hop, jump-off, lavolta, leap,
   leap over, leapfrog, lick, long jump, lop, master, morris,
   mountain, negotiate, objection, obstacle, obstruction, obstructive,
   one small difficulty, over, overjump, overleap, overskip,
   pole vault, pounce, pounce on, pounce upon, restraint, rub,
   running broad jump, running high jump, saut de basque, ski jump,
   skip, snag, spring, start, start aside, start up, steeplechase,
   stumbling block, stumbling stone, surmount, throw, tour jete,
   traverse, updive, upleap, upspring, vault



Bouvier's Law Dictionary, Revised 6th Ed (1856):

HURDLE, Eng. law. A species of sledge, used to draw traitors to execution.