dinner jacket vs tux

dinner jacket and tux both are nouns.

Word	Noun	Adjective	Verb	Adverb
dinner jacket	Yes	No	No	No
tux	Yes	No	No	No

As nouns, dinner jacket and tux are synonyms defined as:

Other synonyms of dinner jacket include black tie, tuxedo.

dinner jacket (noun)	tux (noun)
semiformal evening dress for men	semiformal evening dress for men