auk vs seafowl

auk and seafowl both are nouns.

Word	Noun	Adjective	Verb	Adverb
auk	Yes	No	No	No
seafowl	Yes	No	No	No

As nouns, seafowl is a hypernym of auk; that is, seafowl is a word with a broader meaning than auk:

auk: black-and-white short-necked web-footed diving bird of northern seas
seafowl: a bird that frequents coastal waters and the open ocean: gulls, pelicans, gannets, cormorants, albatrosses, petrels, etc.

Other hypernyms of auk include sea bird, seabird.

auk (noun)	seafowl (noun)
black-and-white short-necked web-footed diving bird of northern seas	a bird that frequents coastal waters and the open ocean: gulls, pelicans, gannets, cormorants, albatrosses, petrels, etc.