jump rope

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

• noun A rope that is twirled and jumped over in children's games or in conditioning exercises.

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

• noun uncountable (also jump-roping, jumping rope) The activity, game or exercise in which a person must jump, bounce or skip repeatedly while a length of rope is swung over and under, both ends held in the hands of the jumper, or alternately, held by two other participants. Often used for athletic training and among schoolchildren. Variations involve speed, chants, varied rope and jumper movement patterns, multiple jumpers and/or multiple ropes.
• noun The length of rope, sometimes with handles, casing or other additions, used in that activity.
• noun colloquial A single jump in this game or activity, counted as a measure of achievement.
• verb idiomatic To repeatedly jump over a rope, the ends of which are held by the jumper or by two others, while the rope is swung under the feet and over the head of the jumper; to play the game of jump rope; to exercise by jumping rope.

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

• noun a length of rope (usually with handles on each end) that is swung around while someone jumps over it
• noun a child's game or a cardiopulmonary exercise in which the player jumps over a swinging rope