Dessert's no good (4)
I believe the answer is:
duff
I believe this is a double definition.
'dessert's' is the first definition.
(duff is a kind of dessert)
'no good' is the second definition.
(I've seen this before)
(Other definitions for duff that I've seen before include "Worthless; pudding" , "Unsuccessful" , "Faulty (slang); a pudding" , "Pudding -- useless -- Homer Simpson's kind of beer" , "Heavy pudding - no good" .)