Put out, as a flame (5)
I believe the answer is:
douse
'put out as a flame' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for douse that I've seen before include "Drench with liquid" , "Drench with water" , "Put out (flame)" , "duck in water" , "Extinguish (a fire)" .)