single tax

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A system by which all revenue is derived from a tax on one thing, especially land.

from the GNU version of the Collaborative International Dictionary of English.

• (Pol. Econ.) A tax levied upon land alone, irrespective of improvements, -- advocated by certain economists as the sole source of public revenue.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a system of taxation in which a tax is levied on a single commodity (usually land)