kingpin

Definitions

• (motorized vehicles) The axis around which steered wheels pivot; a bolt that holds the axis in place—a kingbolt.
• (ten-pin) The pin at the centre of the triangle of bowling pins (originally the tallest pin in kayles). Sometimes also the headpin at the apex.
• The most important person in an undertaking or organization.
• The bolt holding together the truck of a roller skate or skateboard.