Firing oven (4)
I believe the answer is:
kiln
'firing 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 "Pottery-firing oven" , "Hops or pottery cooker?" , "Oven for firing pottery" , "Oven for firing bricks" , "Potter's Friend" .)