Multicameralism

In contrast to unicameralism, multicameralism is the condition in which a legislature is divided into several deliberative assemblies, which are commonly called "chambers" or "houses". This can include bicameralism with two chambers, tricameralism with three, tetracameralism with four branches, or a system with any amount more. The word "multicameral" can also relate in other ways to its literal meaning of "many chambered" with use in science or biology.

Many modern parliaments and congresses adopt a multicameral (usually bicameral) structure to provide multiple perspectives and a form of separation of powers within the legislature.

...
Wikipedia