oligarchy

n. government by a small elite group; people or class selected to rule in an oligarchical government

Oligarchy (Greek , Oligarkhía) is a form of government where political power effectively rests with a small elite segment of society (whether distinguished by wealth, family or military powers). The word oligarchy is from the Greek words for "few" ( óligon) and "rule" ( arkho).
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Noun
1. a political system governed by a few people
(hypernym) political system, form of government

(n.)
A form of government in which the supreme power is placed in the hands of a few persons; also, those who form the ruling few.
  

This name is given to designate the power which a few citizens of a state have usurped, which ought by the constitution to reside in the people. Among the Romans the government degenerated several times into an oligarchy; for example, under the decemvirs when they became the only magistrates in the commonwealth.
   

This entry contains material from Bouvier's Legal Dictionary, a work published in the 1850's.