bow tie vs black tie

bow tie and black tie both are nouns.

Word	Noun	Adjective	Verb	Adverb
bow tie	Yes	No	No	No
black tie	Yes	No	No	No

As nouns, black tie is a hyponym of bow tie; that is, black tie is a word with a more specific, narrower meaning than bow tie:

Other hyponyms of bow tie include white tie.

bow tie (noun)	black tie (noun)
a man's tie that ties in a bow	a black bow tie worn with a dinner jacket
	semiformal evening dress for men