factum noun5 •Somebody's own act and deed. •(Canada) A statement of fact and law delivered before a court.But according to a factum filed by Crown prosecutors, Shaikh's status was "confidential informer," therefore RCMP did not direct him about what to do at the camp. — 2009 •The due execution of a will, including everything necessary to its validity. •Anything stated and made certain. •(no longer used) A product (result of multiplying two numbers). formsfacta · factums