I despise fragmenting walls with dig, incidentally (9)
I believe the answer is:
sideswipe
'i despise fragmenting walls with dig incidentally' is the definition.
I can't judge whether this definition defines the answer.
'i despise fragmenting walls with' is the wordplay.
'fragmenting' indicates an anagram (I've seen 'fragments' mean this (the fragments are put back together differently)).
'walls' indicates putting letters inside (to 'wall' can mean to contain).
'with' becomes 'w' (abbreviation).
'i'+'despise'='idespise'
'idespise' anagrammed gives 'sidesipe'.
'sidesipe' enclosing 'w' is 'SIDESWIPE'.
Can you help me to learn more?
(Other definitions for sideswipe that I've seen before include "Passing stick" , "hardly a terrible blow!" , "critical, incidentally" , "Glancing blow" , "Passing critical remark" .)