vow

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

• noun An earnest promise to perform a specified act or behave in a certain manner, especially a solemn promise to live and act in accordance with the rules of a religious order.
• intransitive verb To promise solemnly; pledge. synonym: promise.
• intransitive verb To make a pledge or threat to undertake.
• intransitive verb To make a vow; promise.
• transitive verb To declare or assert.

from The Century Dictionary.

• noun A solemn promise; an engagement solemnly entered into.
• noun A promise to follow out some line of conduct, or to consecrate or devote one's self wholly or in part for a longer or shorter time to some act or service; a pledge of fidelity or constancy: as, a marriage vow.
• noun A solemn asseveration or declaration; a positive assertion.
• noun A votive offering; an ex-voto.
• To promise solemnly; undertake, by a solemn promise, as to God or a deity, to do, perform, or give; devote.
• To threaten solemnly or upon oath.
• To assert or maintain solemnly; asseverate; swear.
• To make vows or solemn promises; protest solemnly; asseverate; declare emphatically.

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

• intransitive verb To make a vow, or solemn promise.
• noun A solemn promise made to God, or to some deity; an act by which one consecrates or devotes himself, absolutely or conditionally, wholly or in part, for a longer or shorter time, to some act, service, or condition; a devotion of one's possessions.
• noun Specifically, a promise of fidelity; a pledge of love or affection.
• transitive verb To give, consecrate, or dedicate to God, or to some deity, by a solemn promise; to devote; to promise solemnly.
• transitive verb To assert solemnly; to asseverate.

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

• noun A solemn promise to perform some act, or behave in a specified manner, especially a promise to live and act in accordance with the rules of a religious order.
• noun A declaration or assertion.
• verb To make a vow.
• verb To declare publicly that one made a vow, usually to show one's determination or to announce an act of retaliation.

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

• verb dedicate to a deity by a vow
• verb make a vow; promise
• noun a solemn pledge (to oneself or to another or to a deity) to do something or to behave in a certain manner