dinner dress vs evening clothes

dinner dress and evening clothes both are nouns.

Word	Noun	Adjective	Verb	Adverb
dinner dress	Yes	No	No	No
evening clothes	Yes	No	No	No

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

Other hypernyms of dinner dress include evening dress, eveningwear, formalwear, gown.

dinner dress (noun)	evening clothes (noun)
a gown for evening wear	attire to wear on formal occasions in the evening