Pantheon contains nothing but merchandise (5)
I believe the answer is:
goods
'merchandise' is the definition.
(I've seen this in another clue)
'pantheon contains nothing' is the wordplay.
'pantheon' becomes 'gods' (I've seen this in another clue).
'contains' indicates putting letters inside.
'nothing' becomes 'O' (O resembles 0).
'gods' enclosing 'o' is 'GOODS'.
'but' is the link.
(Other definitions for goods that I've seen before include "- - and chattels" , "Commodities" , "Wares" , "Merchandise; freight" , "Merchandise, possessions" .)