A more thorough explanation:

Strict construction is a way of interpreting laws. It means that judges should only apply the exact words of a law, without considering other possible meanings. This is the opposite of liberal construction, which allows judges to consider the overall purpose of a law when interpreting it.

In criminal law, strict construction is especially important. This is because of the rule of lenity, which says that if a law is unclear, it should be interpreted in favor of the defendant. By using strict construction, judges can make sure that defendants are not punished for things that are not clearly illegal.

For example, let's say there is a law that says "it is illegal to carry a weapon in a government building." If someone is caught carrying a knife in a courthouse, a strict constructionist judge would say that the person is guilty, because a knife is a weapon and a courthouse is a government building. A liberal constructionist judge might say that the law was meant to prevent people from bringing guns into government buildings, and that carrying a small knife for self-defense should not be illegal.