impost

Concise Oxford English Dictionary © 2008 Oxford University Press:
impost1 /ˈɪmpəʊst/

▶noun

• 1 a tax or similar compulsory payment.

• 2 Horse Racing the weight carried by a horse as a handicap.

– origin C16: from Fr., from med. L. impostus, from L. impositus, past part. of imponere (see impose).

Concise Oxford English Dictionary © 2008 Oxford University Press:
impost2 /ˈɪmpəʊst/

▶noun Architecture the top course of a pillar that supports an arch.

– origin C15: from Ital. imposta, fem. past part. of imporre, from L. imponere (see impose).