kingpin

plural kingpins

1. automotiveThe axis around which steered wheels pivot; a bolt that holds the axis in place.

   1 more example

   The employees brought back the apparently disappointing news that almost all components showed signs of wear. The sole exceptions were the kingpins, which remained virtually unworn. To the employees’ surprise, [Henry] Ford, instead of expressing pride in his well-made kingpins, declared that the kingpins were overbuilt, and that in the future they should be made more cheaply.

   2000, Jared Diamond, Why Is Sex Fun?, Phoenix, →ISBN, page 152

   Synonyms: kingbolt

2. automotiveThe pivot or connector between a tractor and trailer in the fifth-wheel coupling of semi-trailer truck.
3. figurativelyinformalThe most important person in a usually evil undertaking or organization, often a druglord.

   The rare salarian females are cloistered on their worlds out of tradition and respect. Powerful female Dalatrasses are dynasts and political kingpins. They determine the political course of their respective regions through shrewd negotiation.

   2008, BioWare, Mass Effect, Redwood City: Electronic Arts, →ISBN, →OCLC, PC, scene: Salarians: Culture Codex entry

   1 more example

   As anyone who has ever paid remote attention to global affairs might have predicted, violence has broken out across several Mexican states in the aftermath of the killing – which is generally what happens when you take out a cartel kingpin.

   2026 February 23, Belén Fernández, “El Mencho’s killing won’t solve Mexico’s cartel problem – or anything else”, in Al Jazeera English

   Synonyms: big cheese, big enchilada, top boy, baron, big cheese, big enchilada, big gun, big kahuna

4. ten-pin bowlingThe pin at the centre of the triangle of bowling pins (originally the tallest pin in kayles). Sometimes also the headpin at the apex.
5. The bolt holding together the truck of a roller skate or skateboard.