What a buttonholed listener might do... (3,3,3)
I believe the answer is:
cut and run
'what' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'a buttonholed listener might do' is the wordplay.
I cannot quite understand how this works, but
'a' could be 'an' and 'an' is found in the answer.
'do' could be 'ut' (synonyms) and 'ut' is located in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for cut and run that I've seen before include "A batsman may" , "Make an urgent escape" , "How to deal with short ball" , "get away quickly" , "Make a rapid escape" .)