tricameralism

Tricameralism is the practice of having three legislative or parliamentary chambers. It is contrasted with unicameralism and bicameralism, which are both far more common.

No national government is currently organized along tricameral lines. The word could describe the Ancien Régime era French Estates-General, though similar semantic arguments are applied since it sometimes met in joint session. The South African Parliament established under the apartheid regime's 1983 constitution was tricameral, as was the Chinese 1947 Constitution and Simón Bolívar's model state. A common feature in these bodies, which also casts some doubt on the appropriateness of the name, is that in several cases one of the three legislatures is not principally concerned with legislating.