boastfulness vs vanity

boastfulness and vanity both are nouns.

Word	Noun	Adjective	Verb	Adverb
boastfulness	Yes	No	No	No
vanity	Yes	No	No	No

As nouns, vanity is a hypernym of boastfulness; that is, vanity is a word with a broader meaning than boastfulness:

Other hypernyms of boastfulness include conceit, conceitedness.

boastfulness (noun)	vanity (noun)
outspoken conceit	low table with mirror or mirrors where one sits while dressing or applying makeup
	the trait of being unduly vain and conceited; false pride
	the quality of being valueless or futile
	feelings of excessive pride