In this Act—
the expression " disposition " includes any deed or instrument whereby any land or any estate or interest in land is conveyed or created, other than a lease or a heritable security;
the expression " heritable security " has the like meaning as in the Conveyancing (Scotland) Act, 1924, except that it includes a security constituted by ex facie absolute disposition but does not include a real burden ad factum prcestandum;
the expression " war damage " means damage caused by, or in repelling, enemy action, or by measures taken to avoid the spreading of the consequences of damage caused by, or in repelling, enemy action.