Postpone being freed, possibly (5)
I believe the answer is:
defer
'postpone' is the definition.
(synonyms)
'freed possibly' is the wordplay.
'possibly' indicates anagramming the letters.
'freed' is an anagram of 'DEFER'.
'being' is the link.
(Other definitions for defer that I've seen before include "Postpone - submit" , "Hold back to a later time" , "Put off or give way" , "Give precedence to" , "put on ice" .)