broadbill vs heron

broadbill and heron both are nouns.

Word	Noun	Adjective	Verb	Adverb
broadbill	Yes	No	No	No
heron	Yes	No	No	No

As nouns, heron is a hypernym of broadbill; that is, heron is a word with a broader meaning than broadbill:

broadbill: tropical American heron related to night herons
heron: grey or white wading bird with long neck and long legs and (usually) long bill

broadbill (noun)	heron (noun)
small birds of the Old World tropics having bright plumage and short wide bills	grey or white wading bird with long neck and long legs and (usually) long bill
freshwater duck of the Northern Hemisphere having a broad flat bill
diving ducks of North America having a bluish-grey bill
tropical American heron related to night herons