Vow (?), n. [OE. vou, OF. vou, veu, vo, vu, F. v�u, from L. votum, from vovere, to vow. Cf. Avow, Devout, Vote.]
1. 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. “Nothing... that may... stain my vow of Nazarite.” Milton.
I pray thee, let me go and pay my vow. 2 Sam. xv. 7.
I am combined by a sacred vow. Shak.
2. Specifically, a promise of fidelity; a pledge of love or affection; as, the marriage vow.
Knights of love, who never broke their vow;
Firm to their plighted faith. Dryden.