Alien enemy
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
An alien, that is, a citizen or subject of a foreign state or power, residing within a given country, is calied an "alien ami" if the country where he lives ls at peace with the country of which he is a citizen or subject; but if a state of war exists between the two countries, he is called an "alien enemy," and in that character is denied access to the courts or aid from any of the departments of government.