morning coat vs swallowtail

morning coat and swallowtail both are nouns.

Word	Noun	Adjective	Verb	Adverb
morning coat	Yes	No	No	No
swallowtail	Yes	No	No	No

As nouns, morning coat and swallowtail are synonyms defined as:

morning coat and swallowtail: a man's full-dress jacket with two long tapering tails at the back

Other synonyms of morning coat include swallow-tailed coat.

morning coat (noun)	swallowtail (noun)
a man's full-dress jacket with two long tapering tails at the back	a man's full-dress jacket with two long tapering tails at the back