noun1. a Eurasian plant, Brassica napus (or B. napobrassica), cultivated for its bulbous edible root, which is used as a vegetable and as cattle fodder: family Brassicaceae (crucifers)
2. the root of this plant
3. New Zealand a slang word for head (sense 1)
Also called (for senses 1, 2): Swedish turnip or (US and Canadian) rutabagaWord origin
C19: so called after being introduced into Scotland from Sweden in the 18th century