impost1
 
/
ˈɪmpəʊst/
n.
  - a tax or similar compulsory payment.
 - Horse Racing  the weight carried by a horse as a handicap.
 
Etymology
C16: from Fr., from med. L. impostus, from L. impositus, past part. of imponere (see impose).
impost2
 
/
ˈɪmpəʊst/
n.
 Architecture  the top course of a pillar that supports an arch.
Etymology
C15: from Ital. imposta, fem. past part. of imporre, from L. imponere (see impose).