In this Act, unless the context otherwise requires,—
     (a) "appropriate Government" means, as respects a detention order made by the Central Government or a person detained under such order, the Central Government, and as respects a detention order made by a State Government or by an officer subordinate to a State Government or as respects a person detained under such order, the State Government;
     (b) "detention order" means an order made under section 3;
     (c) "foreigner" has the same meaning as in the Foreigners Act, 1946 (31 of 1946);
     (d) "person" includes a foreigner;
     (e) "State Government", in relation to a Union territory, means the administrator thereof.