martial law n1 : the law applied in occupied territory by the military authority of the occupying power
2 : the law administered by military forces that is invoked by a government in an emergency when civilian law enforcement agencies are unable to maintain public order and safety compare military law
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.