Painter a liability? Partly, among other things (5,4)
I believe the answer is:
inter alia
'among other things' is the definition.
('inter alia' can be a synonym of 'among other things')
'painter a liability? partly' is the wordplay.
'partly' says the answer is hidden in the clue.
'INTER ALIA' can be found hidden inside 'painter a liability'.
(Other definitions for inter alia that I've seen before include "amongst others" , "among others" , "Midst other things" , "amongst other things" , "Among other things, in Latin" .)