He'll give you a good towelling (5)
I believe the answer is:
terry
'towelling' is the definition.
(terry is a kind of towelling)
'he'll give you a good' is the wordplay.
I cannot quite see how this works, but
'good' could be 'err' (I've seen this in another clue) and 'err' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for terry that I've seen before include "Loop of pile fabric; England footballer" , "(Rhyming) man's name" , "A man" , "Fabric with piles" , "Towelling fabric" .)