a private or secret meeting.

an assembly or gathering, esp. one that has special authority, power, or influence

a conclave of political leaders.

the assembly or meeting of the cardinals for the election of a pope.

the body of cardinals; the College of Cardinals.

the place in which the cardinals of the Roman Catholic Church meet in private for the election of a pope.

noun

assembly , buzz session , cabinet * , confab , conference , council , encounter , gathering , get-together , huddle , meet , parley , powwow * , private meeting , session , assemblage , body , company , congregation , congress , convention , convocation , crowd , group , meeting , muster , troop , secret meeting