Q.
What does it mean by "constitution supremacy"?
A.
It means that the Federal Constitution is the supreme law in the federation. It is the fundamental law of the land, a kind of "higher law" which is used as a yardstick with which to measure the validity of all other laws.
Any law inconsistent with the Federal Constitution may be challenged in court. It is higher than the Parliament which is the law making body. As Suffian LP pointed out in Ah Thian v Government of Malaysia:
"The doctrine of supremacy of Parliament does not apply in Malaysia. Here we have a written constitution. The power of Parliament and of State Legislatures in Malaysia is limited by the Constitution, and they cannot make any law they please."
Furthermore, the legislature is not the only organ which is subject to the Federal Constitution, the executive and the judiciary are, too bounded by the Federal Constitution. In short, all institutions created by the Federal Constitution and deriving their power from it are subject to its provisions. This makes it the highest authority in the country, hence its supremacy.
Ref:
Wan Arfah Hamzah (2009) A First Look at the Malaysian Legal System. Oxford Fajar. Pg: 39.