Definition from Wiktionary, the free dictionary
kingpin (plural kingpins)
- (motorized vehicles) The axis around which steered wheels pivot; a bolt that holds the axis in place—a kingbolt.
- (ten-pin bowling) 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.
- (most important person): big cheese, big enchilada, big tamale, big kahuna, bigwig, big wheel, grand poobah, head honcho, muckety muck, top banana, top dog, big noise
most important person