berry vs blackberry

berry and blackberry both are nouns.

Word	Noun	Adjective	Verb	Adverb
berry	Yes	No	Yes	No
blackberry	Yes	No	Yes	No

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

berry: any of numerous small and pulpy edible fruits; used as desserts or in making jams and jellies and preserves
blackberry: large sweet black or very dark purple edible aggregate fruit of any of various bushes of the genus Rubus

As verbs, blackberry is a hyponym of berry; that is, blackberry is a word with a more specific, narrower meaning than berry:

berry (noun)	blackberry (noun)
any of numerous small and pulpy edible fruits; used as desserts or in making jams and jellies and preserves	large sweet black or very dark purple edible aggregate fruit of any of various bushes of the genus Rubus
a small fruit having any of various structures, e.g., simple (grape or blueberry) or aggregate (blackberry or raspberry)	bramble with sweet edible black or dark purple berries that usually do not separate from the receptacle

berry (verb)	blackberry (verb)
pick or gather berries	pick or gather blackberries