= supramarginal .
2Better or more than marginal in quality or degree; (Economics) involving or achieving a greater than marginal level of profit or value.
Of land or ore: of greater profitability than marginal land or ore. Of a farmer, etc.: working such land.
Designating a constituency, etc., in which an election is expected to be extremely closely contested, the sitting or outgoing member typically having only a very small majority.
rare A supermarginal part; especially one of the plates lying above the marginal plates of a starfish arm.
A supermarginal constituency or seat.
Mid 19th century; earliest use found in James Dana (1813–1895), geologist, zoologist, and teacher. From super- + marginal.