Pottery oven (4)
I believe the answer is:
kiln
'pottery oven' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for kiln that I've seen before include "Industrial oven" , "Pottery-firing oven" , "Furnace for firing bricks" , "Potter's Friend" , "Large oven, for potters say" .)