Answer:
A system where each branch of government shares powers with the other branches to limit their actions.
Explanation:
Ex. The executive branch (President) may veto a law passed by Congress, however the legislative branch can override it with a minimum of a 2/3 vote form both the House and the Senate.
Ex. The executive branch can appoint people to federal positions, however the Senate must "Advise and Consent" meaning they must confirm the appointment
Ex. The judicial branch can declare laws unconstitutional, however the legislative branch can hold a vote to overrule it.
Ex. The executive branch can declare executive orders, however the judicial branch can declare acts unconstitutional.