Definition of supermarginal in English:

1Zoology and Anatomy= supramarginal.

2Better or more than marginal in quality or degree; (Economics) involving or achieving a greater than marginal level of profit or value.

3Economics. Of land or ore: of greater profitability than marginal land or ore. Of a farmer, etc.: working such land.

4Politics. 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.

1Zoology. A supermarginal part; especially one of the plates lying above the marginal plates of a starfish arm. rare.

2Politics. A supermarginal constituency or seat.