“Estate” means -any land which is entered on the revenue-roll as separately assessed with the public revenue ;
any land acquired from the [Government] under one title, which is liable to pay land-revenue at any future time; any char or island thrown up in a navigable river or in the sea which under the laws in force is at the disposal of the [Government];
any land which is entered on the Collector’s registers as a separate holding, free in perpetuity from liability to pay land-revenue;
any land gained by alluvion or by dereliction of a river or of the sea to any estate as here defined, which under the laws in force, is considered an increment to the tenure to which such land has accreted, shall be deemed a part of such estate;
Bengal Survey Act, 1875.