swallow-tailed coat vs morning coat

swallow-tailed coat and morning coat both are nouns.

Word	Noun	Adjective	Verb	Adverb
swallow-tailed coat	Yes	No	No	No
morning coat	Yes	No	No	No

As nouns, swallow-tailed coat and morning coat are synonyms defined as:

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

Other synonyms of swallow-tailed coat include swallowtail.

swallow-tailed coat (noun)	morning coat (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