struggle

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

• intransitive verb To exert muscular energy, as against a material force or mass.
• intransitive verb To be strenuously engaged with a problem, task, or undertaking.
• intransitive verb To have difficulty or make a strenuous effort doing something.
• intransitive verb To move or progress with difficulty.
• intransitive verb To contend or compete.
• intransitive verb To move or place (something) with an effort.
• noun The act of struggling.
• noun A strenuous effort in the face of difficulty.
• noun Strife, contention, or combat.
• noun Something that is difficult to do or achieve.

from The Century Dictionary.

• To put forth violent effort, as in an emergency or as a result of intense excitation; act or strive strenuously against some antagonistic force or influence; be engaged in an earnest effort or conflict; labor or contend urgently, as for some object: used chiefly of persons, but also, figuratively, of things.
• Synonyms Strive, etc. (see attempt); toil.
• noun A violent effort; a strenuous or straining exertion; a strenuous endeavor to accomplish, avoid, or escape something; a contest with some opposing force: as, a struggle to get free; the struggle of death; a struggle with poverty.
• noun Synonyms Endeavor. Effort, Exertion, Pains, Labor. Struggle. See strife. The above are in the order of strength.

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

• noun A violent effort or efforts with contortions of the body; agony; distress.
• noun Great labor; forcible effort to obtain an object, or to avert an evil.
• noun Contest; contention; strife.
• intransitive verb To strive, or to make efforts, with a twisting, or with contortions of the body.
• intransitive verb To use great efforts; to labor hard; to strive; to contend forcibly.
• intransitive verb To labor in pain or anguish; to be in agony; to labor in any kind of difficulty or distress.

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

• noun strife, contention, great effort
• verb to strive, to labour in difficulty, to fight (for or against), to contend.

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

• verb make a strenuous or labored effort
• noun an energetic attempt to achieve something
• noun an open clash between two opposing groups (or individuals)
• noun strenuous effort
• verb climb awkwardly, as if by scrambling
• verb to exert strenuous effort against opposition
• verb be engaged in a fight; carry on a fight