Upset patent ash container (8)
I believe the answer is:
overturn
'upset' is the definition.
(I know this)
'patent ash container' is the wordplay.
'patent' becomes 'overt' (both can mean obvious).
'ash container' becomes 'urn' (I've seen this in another clue).
'overt'+'urn'='OVERTURN'
(Other definitions for overturn that I've seen before include "Invalidate - upset" , "Reverse previous findings" , "Invert" , "Upset; abolish" , "Revoke" .)