Yes. South Africa really did have a tricameral Parliament under the 1983 Constitution, in force from 1984 until the democratic transition. But the phrase can mislead, because it sounds more pluralistic than it really was. The system created three racially separate parliamentary chambers: a House of Assembly for whites, a House of Representatives for Coloured South Africans, and a House of Delegates for Indian South Africans. The black African majority was excluded altogether from this Parliament.

The key to how it worked was the distinction between “own affairs” and “general affairs.” Each chamber could legislate for the “own affairs” of the racial group it represented; these included areas such as education, housing, welfare, local government, culture, and recreation. But the central levers of power—“general affairs”—remained matters such as defence, finance, foreign policy, justice, law and order, commerce, internal affairs, and agriculture. Those were handled at the center, not by the separate chambers acting independently.

Formally, then, it was a three-house legislature. In practice, it was a system of segregated representation plus retained white dominance. The constitutional text itself says Parliament consisted of the three Houses. But the white chamber was far larger and more institutionally powerful: the House of Assembly had 178 members, while the House of Representatives had 85 and the House of Delegates 45. The Constitution also vested executive authority in the State President, with different advisory structures for “own affairs” and “general affairs,” which further centralized power above the chambers themselves.

Here is the full GPT discussion, with links as well.  As Harrison points out to me, in history tricameralism of any form is extremely rare.