noun

• The governing council and chief policymaking body of the Communist Party of the Soviet Union and other Marxist-Leninist political systems.
• (by extension, sometimes derogatory) A senior governing or policymaking body in a political or other organization, generally consisting of members who are either appointed by the party in control of the organization, or who attain membership through their personal political affiliations.
• Any of various politburos, especially that of the Soviet Union or that of the People's Republic of China.
• (metonymically) The senior leadership of the Soviet Union, or that of the People's Republic of China.