heron vs broadbill

heron and broadbill both are nouns.

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

As nouns, broadbill is a hyponym of heron; that is, broadbill is a word with a more specific, narrower meaning than heron:

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

heron (noun)	broadbill (noun)
grey or white wading bird with long neck and long legs and (usually) long bill	small birds of the Old World tropics having bright plumage and short wide bills
	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