Definition of vow (noun)
- a solemn pledge (to oneself or to another or to a deity) to do something or to behave in a certain manner
- "they took vows of poverty"
Definition of vow (verb)
- make a vow; promise
- "He vowed never to drink alcohol again"
- dedicate to a deity by a vow
- synonyms: consecrate
Source: Princeton University Wordnet