Tax or levy (5)
I believe the answer is:
tithe
This clue is a double definition.
'tax' is the first definition.
(I've seen this before)
'levy' is the second definition.
(tithe is a kind of levy)
'or' acts as a link.
(Other definitions for tithe that I've seen before include "Church payment" , "Offering" , "Source of church revenue" , "Former church tax" , "Tax paid to church" .)