grapefruit Fruit of Citrus paradisi; thought to have arisen as a sport of the pomelo or shaddock (Citrus grandis), a coarser citrus fruit, or as a hybrid between pomelo and sweet orange. It contains 35–40 mg vitamin C per 100 g. The pith contains naringin, which is very bitter. Named by the botanist John Lunan in Hortus Jamaicanensis (1814) because the fruits grow in “grape‐like” clusters. The ruby grapefruit, with red flesh, was discovered as a sport in Texas in 1929.

grape·fruit / ˈgrāpˌfroōt/ • n. (pl. same) 1. a large, round, yellow citrus fruit with an acid, juicy pulp. 2. the tree (Citrus paradisi) bearing this fruit.

grapefruit Evergreen citrus fruit tree and its yellow, edible fruit, which is a valuable source of vitamin C. The tree may reach 6m (20ft), and is grown mainly in subtropical climates in the USA, Israel, South Africa and Argentina. Family Rutaceae.

grapefruit See CITRUS.