What is the meaning of the Latin Maxim 'Ex Post Facto'?

of the same kind and nature through lack of care that which is said in passing from a thing done afterward

from a thing done afterward

Ex Post Facto: It is Latin for "from a thing done afterward". Ex post facto is a Latin phrase that essentially means "retroactive," or affecting something that's already happened. Approval for a project that's given ex post facto—after the project already has been begun or completed. A law that makes chewing gum illegal and requires the arrest of every person who has ever chewed gum, even before the law existed, would be an example of an ex post facto law.