Quagmire (6)
I believe the answer is:
morass
'quagmire' is the definition.
(I know that quagmire can be written as morass)
This is all the clue.
(Other definitions for morass that I've seen before include "Muddled situation" , "Tract of soft, wet ground" , "Slough - marsh" , "Area of marshy or swampy ground" , "Mire, quagmire" .)