Pottery furnace (4)
I believe the answer is:
kiln
'pottery furnace' 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 "Baker" , "Pottery-firing oven" , "Oven for firing bricks" , "Oven for hardening and drying" , "Large oven for baking pottery" .)