Sack about a ditch (8)
I believe the answer is:
retrench
'sack' is the definition.
The answer and definition can be both to do with ownership as well as being verbs in their base form.
Maybe there's an association between them I don't understand?
'about a ditch' is the wordplay.
'about' becomes 're' (regarding).
'a ditch' becomes 'trench' (trench is a kind of ditch).
're'+'trench'='RETRENCH'
Can you help me to learn more?
(Other definitions for retrench that I've seen before include "Reduce expenses" , "Reduce spending in response to economic difficulty" , "Cut back expenses" , "Once more dig deep" , "Bring down" .)