black tie vs evening clothes

black tie and evening clothes both are nouns.

Word	Noun	Adjective	Verb	Adverb
black tie	Yes	No	No	No
evening clothes	Yes	No	No	No

As nouns, evening clothes is a hypernym of black tie; that is, evening clothes is a word with a broader meaning than black tie:

Other hypernyms of black tie include evening dress, eveningwear, formalwear.

black tie (noun)	evening clothes (noun)
a black bow tie worn with a dinner jacket	attire to wear on formal occasions in the evening
semiformal evening dress for men