D defs.my
Entry 2 senses Webster, 1913

Impost

· Im·post · IPA /ˈɪmpoʊst/
01 n. That which is imposed or levied; a tax, tribute, or duty; especially, a duty or tax laid by goverment on goods imported into a country.
  1. 1.
    That which is imposed or levied; a tax, tribute, or duty; especially, a duty or tax laid by goverment on goods imported into a country.
    “Even the ship money . . . Johnson could not pronounce to have been an unconstitutional impost.” Macaulay.
  2. 2.
    The top member of a pillar, pier, wall, etc., upon which the weight of an arch rests.(Arch.)