a tax, tariff or duty etc. that is imposed. Unlike taxes, tariffs, or duties, the primary purpose of an impost is to dissuade countries from discriminating against the imports or shipping of other nations. If the trade is non-discriminatory, then no impost is generally levied. It is therefore not intended as a revenue source, but rather as a way to regulate commerce
A block in the shape of a truncated pyramid, placed above the capital instead of an abacus