Deals with the woodworm and has no more nonsense (5,3,3)
I believe the answer is:
stops the rot
'deals' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'the woodworm and has no more nonsense' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
'no' could be 'o' (O resembles 0) and 'o' is found in the answer.
'nonsense' could be 'rot' (rot can mean nonsense or rubbish) and 'rot' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'with' acts as a link.
Can you help me to learn more?
(Another definition for stops the rot that I've seen is " Arrests decay or decline".)