(Fig.) The most important person within a particular organization, either legitimate or illegitimate

After having arrested countless pushers, finally the police was able to get its hands on the drug kingpins of the city, thus dealing a fatal blow to organized crime

Finalmente la polizia, dopo aver arrestato innumerevoli piccoli spacciatori, è riuscita a metter le mani sui pezzi da 90 del traffico della droga in città, dando così un colpo mortale all'organizzazione criminale

The government hired seven of the deadliest action specialists to take on seven crime kingpins

Lo stato ha ingaggiato sette specialisti senza scrupoli per dare la caccia a sette grossi calibri del crimine

Kingpin or king pin, originally a target in early ball games, has taken on a meaning of 'key component' and metaphorically of 'boss'