tail coat vs white tie

tail coat and white tie both are nouns.

Word	Noun	Adjective	Verb	Adverb
tail coat	Yes	No	No	No
white tie	Yes	No	No	No

As nouns, tail coat and white tie are synonyms defined as:

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

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

tail coat (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