One way to be free of cost, possibly (4)
I believe the answer is:
scot
'one way to be free' is the definition.
(I've seen this in another clue)
'cost possibly' is the wordplay.
'possibly' is an anagram indicator.
'cost' anagrammed gives 'SCOT'.
'of' acts as a link.
(Other definitions for scot that I've seen before include "9 [KEIR HARDIE], say" , "Highlander perhaps" , "Native of Glasgow, say" , "National" , "Burns for one" .)