full dress vs tail coat

full dress and tail coat both are nouns.

Word	Noun	Adjective	Verb	Adverb
full dress	Yes	No	No	No
tail coat	Yes	No	No	No

As nouns, full dress and tail coat are synonyms defined as:

full dress and tail coat: formalwear consisting of full evening dress for men

Other synonyms of full dress include dress suit, tailcoat, tails, white tie, white tie and tails.

full dress (noun)	tail coat (noun)
formalwear consisting of full evening dress for men	formalwear consisting of full evening dress for men