A person who is in charge of a criminal organization.
The most important person in an undertaking or organization.
The axis around which steered wheels pivot; a bolt that holds the axis in place—a kingbolt.
The bolt holding together the truck of a roller skate or skateboard.
The pivot or connector between a tractor and trailer in the fifth-wheel coupling of semi-trailer truck.
The pin at the centre of the triangle of bowling pins (originally the tallest pin in kayles). Sometimes also the headpin at the apex.