From Longman Dictionary of Contemporary Englishkingpinking‧pin /ˈkɪŋˌpɪn/ noun [countable usually singular] 1 IMPORTANTthe person or thing in a group that is the most important or that has the most power – used especially in news reportscrime/drug etc kingpin a mafia kingpin2 technicalT a thin strong piece of metal used in hinges
