In modern political science, the term polyarchy (poly `many`, arkhe `rule`) was used by Robert Dahl to describe a form of government in which power is invested in multiple people. It takes form of neither dictatorship nor democracy. This form of government was first implemented in the United States and France and was gradually adopted by many ...
government by many people
• (n.) A government by many persons, of whatever order or class.
Robert Dahl's term for pluralist forms of liberal democracy, in which there is competition between many different interests.
Pol'y·ar`chy noun [ Poly- + -archy : confer French polyarchie. Confer Polarchy .] A government by many persons, of whatever order or class. Cudworth. 
polyarchy, polarchy, polygarchy The government of a state or city by many: contrasted with monarchy.