Mossy wetland (4,3)
I believe the answer is:
peat-bog
'mossy wetland' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for peat-bog that I've seen before include "Boat peg (anag.)" , "Source of vegetable fuel" , "Wet spongy ground, cut and dried for fuel" .)