tailcoat vs white tie and tails

tailcoat and white tie and tails both are nouns.

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

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

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

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

tailcoat (noun)	white tie and tails (noun)
formalwear consisting of full evening dress for men	formalwear consisting of full evening dress for men