Crummy pudding (4)

I believe the answer is:

duff

I believe this is a double definition.

'crummy' is the first definition.
(both can mean low-quality)

'pudding' is the second definition.
(duff is a kind of pudding)

(Other definitions for duff that I've seen before include "Dud - pud" , "False; steamed pudding" , "Faulty (slang); a pudding" , "Pudding -- useless -- Homer Simpson's kind of beer" , "Heavy pudding - no good" .)

I've seen this clue in The Times.

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