vi to make a vow, or solemn promise.
2. vow ·noun to assert solemnly; to asseverate.
3. vow ·noun specifically, a promise of fidelity; a pledge of love or affection; as, the marriage vow.
4. vow ·noun to give, consecrate, or dedicate to god, or to some deity, by a solemn promise; to devote; to promise solemnly.
5. vow ·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; as, a baptismal vow; a vow of poverty.