...postpone or carry on? (4,4)
I believe the answer is:
hold over
'postpone' is the definition.
('hold over' can be a synonym of 'postpone')
'carry on?' is the wordplay.
'carry' becomes 'hold' ('hold' can be a synonym of 'carry'**).
'on?' becomes 'over' (I've seen this before).
'hold'+'over'='HOLD OVER'
'or' acts as a link.
(Other definitions for hold over that I've seen before include "... postpone" , "influence on another" , "Defer action on" .)