fidget

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

• intransitive verb To behave or move nervously or restlessly.
• intransitive verb To play or fuss; fiddle.
• intransitive verb To cause to behave or move nervously or restlessly.
• noun A condition of restlessness as manifested by nervous movements. Often used with the:
• noun One that fidgets.

from The Century Dictionary.

• To move uneasily one way and the other; move irregularly, or in fits and starts; be restless or uneasy; show impatience or uneasiness by restless movements.
• To make restless, nervous, or fidgety.
• noun The expression of uneasiness, restlessness, impatience, etc., by irregular spasmodic movements and changes of physical expression; the condition of feeling thus expressed: commonly in the plural: as, to be in a fidget or the fidgets; to have the fidgets.

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

• intransitive verb To move uneasily one way and the other; to move irregularly, or by fits and starts.
• noun Uneasiness; restlessness.
• noun A general nervous restlessness, manifested by incessant changes of position; dysphoria.

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

• verb intransitive to wiggle or twitch; to move around nervously or idly
• noun informal A person who fidgets, especially habitually.

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

• noun a feeling of agitation expressed in continual motion
• verb move restlessly