Real Dictionary

martial law
uncountable noun: Martial law is control of an area by soldiers, not the police.

martial law in American English
the law temporarily imposed upon an area by state or national military forces when civil authority has broken down or during wartime military operations

martial law in British English
temporary rule by the military authorities over the civilian population, as in an area of military operations in time of war, or when civil authority has broken down
noun: the rule of law established and maintained by the military in the absence of civil law