Suffer through short treatment (5)
I believe the answer is:
incur
'suffer' is the definition.
(I've seen this before)
'through short treatment' is the wordplay.
'through' becomes 'in'.
'short' means to remove the last letter.
'treatment' becomes 'cure' (cure is a kind of treatment).
'cure' with its last letter taken off is 'cur'.
'in'+'cur'='INCUR'
(Other definitions for incur that I've seen before include "Bring on as a consequence" , "Invite, bring about" , "contract" , "To become liable to, suffer" , "Bring on oneself, say costs" .)