Taxes, duties, or impositions. A duty on imported goods or merchandise. Impost is a tax received by the prince for such merchandises as are brought into any haven within his dominions from foreign nations. It may in some sort be distinguished from customs, because customs are rather that profit the prince maketh of wares shipped out; yet they are frequently confounded. Cowell.
IMPOSTS
TheLaw.com Law Dictionary & Black's Law Dictionary 2nd Ed.