Complain doctor’s consuming alcohol (5)
I believe the answer is:
grump
'alcohol' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'complain doctor's consuming' is the wordplay.
'complain' becomes 'rum' (I can't explain this - if you can you should believe this answer much more).
'doctor' becomes 'GP' (general practitioner).
'consuming' is an insertion indicator.
'rum' placed into 'gp' is 'GRUMP'.
Can you help me to learn more?
(Other definitions for grump that I've seen before include "Sulky type" , "Sulky person" , "pet?" , "grouse" , "Crosspatch" .)