kingpin

UK: /ˈkɪŋpɪn/ US: /ˈkɪŋˌpɪn/ ,(king′pin′)

WordReference Random House Learner's Dictionary of American English © 2026

king•pin /ˈkɪŋˌpɪn/   n. [countable]

1. [Informal.] a person or thing of chief importance:
   He's the kingpin of the entire organization.
2. Automotive the central pin in bowling.

WordReference Random House Unabridged Dictionary of American English © 2026

king•pin  (king′pin′), n. 

1. [Bowling.]
   • headpin.
   • the pin at the center;
     the number five pin.
2. [Informal.] the person of chief importance in a corporation, movement, undertaking, etc.
3. [Informal.] the chief element of any system, plan, or the like.
4. Rail Transport a kingbolt.
5. Automotive either of the pins that are a part of the mechanism for turning the front wheels in some automotive steering systems.

• king + pin 1795–1805

Collins Concise English Dictionary © HarperCollins Publishers::

kingpin / ˈkɪŋˌpɪn/ noun

1. the most important person in an organization
2. Also called (Brit): swivel pin a pivot pin that provides a steering joint in a motor vehicle by securing the stub axle to the axle beam
3. the front pin in the triangular arrangement of the ten pins
4. (in ninepins) the central pin in the diamond pattern of the nine pins