sea bird vs seafowl

sea bird and seafowl both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea bird	Yes	No	No	No
seafowl	Yes	No	No	No

As nouns, sea bird and seafowl are synonyms defined as:

sea bird and seafowl: a bird that frequents coastal waters and the open ocean: gulls, pelicans, gannets, cormorants, albatrosses, petrels, etc.

Other synonyms of sea bird include seabird.

sea bird (noun)	seafowl (noun)
a bird that frequents coastal waters and the open ocean: gulls, pelicans, gannets, cormorants, albatrosses, petrels, etc.	a bird that frequents coastal waters and the open ocean: gulls, pelicans, gannets, cormorants, albatrosses, petrels, etc.