buckeye

noun

• 1a North American tree or shrub related to the horse chestnut, with showy yellow, red, or white flowers.

  • Genus Aesculus, family Hippocastanaceae: several species, including the Ohio buckeye (A. glabra), with yellow flowers and prickly fruit husks

• 2 (also buckeye butterfly) an orange and brown New World butterfly with conspicuous eyespots on the wings.

  • Junonia coenia, subfamily Nymphalinae, family Nymphalidae

• 3 (Buckeye) US informal a native of the state of Ohio.

  [from the name given to the state, with reference to the abundance of buckeye trees]

• 4 (also buckeye coupling) a kind of automatic coupling for railroad rolling stock.

  [named after the Buckeye Steel Castings Company, Columbus, Ohio]