tail coat vs tailcoat

tail coat and tailcoat both are nouns.

Word	Noun	Adjective	Verb	Adverb
tail coat	Yes	No	No	No
tailcoat	Yes	No	No	No

As nouns, tail coat and tailcoat are synonyms defined as:

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

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

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