vow / vou/ • n. a solemn promise. ∎ (vows) a set of such promises committing one to a prescribed role, calling, or course of action, typically to marriage or a monastic career.• v. 1. solemnly promise to do a specified thing: he vowed that his government would not tolerate a repeat of the disorder | [with direct speech] one fan vowed, “I'll picket every home game.” 2. [tr.] archaic dedicate to someone or something, esp. a deity: I vowed myself to this enterprise.
So vow vb. make a vow. XIII. — (O)F. vouer.