evening dress vs formalwear

evening dress and formalwear both are nouns.

Word	Noun	Adjective	Verb	Adverb
evening dress	Yes	No	No	No
formalwear	Yes	No	No	No

As nouns, evening dress and formalwear are synonyms defined as:

evening dress and formalwear: attire to wear on formal occasions in the evening

Other synonyms of evening dress include evening clothes, eveningwear.

evening dress (noun)	formalwear (noun)
attire to wear on formal occasions in the evening	attire to wear on formal occasions in the evening