separation of powers: The principle of American government whereby power is distributed among three branches of government. Members of each branch are selected via different procedures, have different terms of office, and are independent of each other. The separation is not complete as each shares the power of the other (see checks and balances). WHile the benefit is an inability for any branch to dominate, the fragmentation of power and its attendant gravitation to gridlock/ stalemate is a major factor in the operation of the American political system. The judiciary plays a dominant role in determining the contemporary powers of each branch through it power of interpretation (see judicial review).

Paraphrase from: The American Political Dictionary