Definitions for "Separation of powers"
The idea that the powers of a government should be split between two or more independent groups, so that any one person or group cannot gain too much power. For example, in the US Constitution, governmental power is split among the Legislative, Executive, and Judicial Branches.
The doctrine which allocates to the legislature the power to make the law, to the executive the power to put it into effect, and to the judiciary the power to settle disputes arising under the law.
Division of governmental power among several institutions that must cooperate in decision making.