Definition of Madagascar periwinkle in US English:

Madagascar periwinkle

noun

  • An ornamental pink- or white-flowered plant, Catharanthus roseus (family Apocynaceae), perhaps native to tropical America, and widely cultivated and naturalized elsewhere in the tropics (the plant is the source of the drugs vincristine and vinblastine).

Origin

Early 19th century; earliest use found in Thomas Martyn (1735–1825), botanist.