Potter’s oven (4)
I believe the answer is:
kiln
'potter's oven' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for kiln that I've seen before include "Industrial oven" , "Industrial furnace" , "Hops or pottery cooker?" , "Oven for firing ceramics etc" , "Pottery furnace" .)