- a type of bramble: a hybrid of the loganberry and various blackberries and raspberries
- the large red edible fruit of this plant
WordReference Random House Learner's Dictionary of American English © 2017
- Plant Biologya fruit like a blackberry with a flavor similar to that of a raspberry:boysenberry jam.
- Plant Biologya blackberrylike fruit with a flavor similar to that of raspberries, developed by crossing various plants of the genus Rubus.
- named after R. Boysen, 20th-century American botanist, who bred it 1930–35