oligarchy

/ˈɒlɪgɑːki/ noun (plural oligarchies) GOVERNMENT, ECONOMICS

Definition

› [U] the fact of a country being ruled or controlled by a small group of powerful people: The real difference between oligarchy and democracy is wealth.

› [C] a country or industry that is controlled by a small group of powerful people, or these people considered as a group: The electricity industry has moved from being a state monopoly to being a de facto oligarchy.

(Definition of oligarchy noun from the Cambridge Business English Dictionary © Cambridge University Press)