gull vs blackcap

gull and blackcap both are nouns.

Word	Noun	Adjective	Verb	Adverb
gull	Yes	No	Yes	No
blackcap	Yes	No	No	No

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

gull (noun)	blackcap (noun)
mostly white aquatic bird having long pointed wings and short legs	small brownish-grey warbler with a black crown
a person who is gullible and easy to take advantage of	chickadee having a dark crown
	small black-headed European gull
	raspberry native to eastern North America having black thimble-shaped fruit

gull (verb)	blackcap (verb)
fool or hoax
make a fool or dupe of