puffin vs seabird

puffin and seabird both are nouns.

Word	Noun	Adjective	Verb	Adverb
puffin	Yes	No	No	No
seabird	Yes	No	No	No

As nouns, seabird is a hypernym of puffin; that is, seabird is a word with a broader meaning than puffin:

puffin: any of two genera of northern seabirds having short necks and brightly colored compressed bills
seabird: a bird that frequents coastal waters and the open ocean: gulls, pelicans, gannets, cormorants, albatrosses, petrels, etc.

Other hypernyms of puffin include sea bird, seafowl.

puffin (noun)	seabird (noun)
any of two genera of northern seabirds having short necks and brightly colored compressed bills	a bird that frequents coastal waters and the open ocean: gulls, pelicans, gannets, cormorants, albatrosses, petrels, etc.