wing nut

noun

• 1 (also wingnut) a nut with a pair of projections for the fingers to screw it on.

• 2an Asian tree of the walnut family, with a deeply fissured trunk, compound leaves, and characteristic broad-winged nutlets.

  • Genus Pterocarya, family Juglandaceae

• 3 (wingnut) informal a mad or crazy person:some wingnut down in Finance
• a person with extreme, typically right-wing, views:McCarthyite wingnuts