What is certus in re English?

The phrase "certus in re" is a Latin expression that means "certain in the thing." It is often used in legal contexts to refer to a fact that is not in dispute or that has been established by clear and convincing evidence. For example, in a criminal case, the prosecution might argue that the defendant is "certus in re" with respect to the crime charged, meaning that there is no doubt that the defendant committed the crime.