Postpone being freed, perhaps (5)
I believe the answer is:
defer
'postpone' is the definition.
(I know that postpone can be written as defer)
'freed perhaps' is the wordplay.
'perhaps' indicates anagramming the letters.
'freed' with letters rearranged gives 'DEFER'.
'being' is the link.
(Other definitions for defer that I've seen before include "Yield to another's opinion" , "Put off to another time" , "Hold back to a later time" , "Capitulate" , "Put off to later time" .)