hurdle

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A light portable barrier over which competitors must leap in certain races.
• noun A race in which a series of such barriers must be jumped without the competitors' breaking their stride.
• noun A leaping step made off one foot as means of maximizing spring at the end of an approach, as to a dive.
• noun An obstacle or difficulty to be overcome.
• noun Chiefly British A portable framework made of intertwined branches or wattle and used for temporary fencing.
• noun Chiefly British A frame or sledge on which condemned persons were dragged to execution.
• intransitive verb To leap over (a barrier) in or as if in a race.
• intransitive verb To overcome or deal with successfully; surmount.
• intransitive verb To leap over a barrier or other obstacle.

from The Century Dictionary.

• To jump over a hurdle, as in a hurdle-race; hence, to jump over anything as if it were a hurdle.
• To make, hedge, cover, or close with hurdles.
• noun A movable frame made of interlaced twigs or sticks, or of bars, rods, or narrow boards, crossing each other.
• noun Specifically— A sledge or frame on which criminals were formerly drawn to the place of execution.
• noun In fortification, a collection of twigs or sticks interwoven closely and sustained by long stakes, made usually of a rectangular shape, 5 or 6 feet by 3½ feet, and serving to render works firm or to cover traverses and lodgments for the defense of workmen against fireworks or stones.
• noun In agriculture: A frame usually made of wood, but sometimes of iron, for the purpose of forming temporary fences. When a fence is to be formed of hurdles, they are put down end to end, and fastened to the ground and to one another.
• noun A space inclosed by hurdles: a fold.
• noun A kind of permanent mattress of willow or other branches, built on a river-bank and fastened down with short sticks, to prevent the wearing away of the bank by the current of the stream.
• noun In racing, a bar or frame placed across a race-course at a certain height, in semblance of a fence, to be cleared by the contesting men or horses.
• noun In hat-making, a grid or frame of wood or wire, in which a mass of felting-hair is placed to be bowed.

from the GNU version of the Collaborative International Dictionary of English.

• noun 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.
• noun In England, a sled or crate on which criminals were formerly drawn to the place of execution.
• noun An artificial barrier, variously constructed, over which men or horses leap in a race.
• noun a race in which artificial barriers in the form of hurdles, fences, etc., must be leaped.
• transitive verb To hedge, cover, make, or inclose with hurdles.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An artificial barrier, variously constructed, over which men or horses jump in a race.
• noun A perceived obstacle.
• noun A movable frame of wattled twigs, osiers, or withes and stakes, or sometimes of iron, used for enclosing land, for folding sheep and cattle, for gates, etc.; also, in fortification, used as revetments, and for other purposes.
• noun UK, obsolete A sled or crate on which criminals were formerly drawn to the place of execution.
• verb To jump over something while running.
• verb To compete in the track and field events of hurdles (e.g. high hurdles).
• verb To overcome an obstacle.
• verb To hedge, cover, make, or enclose with hurdles.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a light movable barrier that competitors must leap over in certain races
• noun an obstacle that you are expected to overcome
• noun the act of jumping over an obstacle
• verb jump a hurdle