swamphen vs marsh hen

swamphen and marsh hen both are nouns.

Word	Noun	Adjective	Verb	Adverb
swamphen	Yes	No	No	No
marsh hen	Yes	No	No	No

As nouns, swamphen and marsh hen are synonyms defined as:

swamphen and marsh hen: any of various small aquatic birds of the genus Gallinula distinguished from rails by a frontal shield and a resemblance to domestic hens

Other synonyms of swamphen include gallinule, water hen.

swamphen (noun)	marsh hen (noun)
any of various small aquatic birds of the genus Gallinula distinguished from rails by a frontal shield and a resemblance to domestic hens	any of various small aquatic birds of the genus Gallinula distinguished from rails by a frontal shield and a resemblance to domestic hens
	a coot found in North America