Polytheist keeps silver in pot (5)
I believe the answer is:
pagan
'polytheist' is the definition.
(I've seen this in another clue)
'silver in pot' is the wordplay.
'silver' becomes 'Ag' (Ag is the chemical symbol for silver).
'in' is an insertion indicator.
'pot' becomes 'pan' (I've seen this before).
'ag' placed into 'pan' is 'PAGAN'.
'keeps' acts as a link.
(Other definitions for pagan that I've seen before include "One who does not acknowledge your god(s)" , "Not conventionally religious" , "One outside the main religions" , "A heathen, not a Christian" , "One who does not acknowledge a god" .)