blackberry (n.)

"fruit of the bramble," early 12c., from Old English blaceberian, from black (adj.) + berry. So called for the color. Also in Old English as bremelberie, bremelæppel (from bramble). The wireless handheld device of the same name was introduced 1999. Related: Blackberrying.

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Definitions of blackberry from WordNet
blackberry (n.)
large sweet black or very dark purple edible aggregate fruit of any of various bushes of the genus Rubus;
blackberry (n.)
bramble with sweet edible black or dark purple berries that usually do not separate from the receptacle;
Synonyms: blackberry bush
blackberry (v.)
pick or gather blackberries;
The children went blackberrying