swear vs vow

swear is not a noun while vow is a noun.

Word	Noun	Adjective	Verb	Adverb
swear	No	No	Yes	No
vow	Yes	No	Yes	No

As verbs, vow is a hypernym of swear; that is, vow is a word with a broader meaning than swear:

swear (noun)	vow (noun)
	a solemn pledge (to oneself or to another or to a deity) to do something or to behave in a certain manner

swear (verb)	vow (verb)
have faith or confidence in	make a vow; promise
make a deposition; declare under oath	dedicate to a deity by a vow
utter obscenities or profanities
promise solemnly; take an oath
to declare or affirm solemnly and formally as true