tails vs white tie

tails and white tie both are nouns.

Word	Noun	Adjective	Verb	Adverb
tails	Yes	No	No	No
white tie	Yes	No	No	No

As nouns, tails and white tie are synonyms defined as:

tails and white tie: formalwear consisting of full evening dress for men

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

tails (noun)	white tie (noun)
formalwear consisting of full evening dress for men	bow tie worn as part of a man's formal evening dress
	formalwear consisting of full evening dress for men