Bind or untie, possibly (5)
I believe the answer is:
unite
'bind' is the definition.
(I've seen this in another clue)
'untie possibly' is the wordplay.
'possibly' indicates anagramming the letters.
'untie' anagrammed gives 'UNITE'.
'or' is the link.
(Other definitions for unite that I've seen before include "Link" , "Club together" , "Get together" , "Join together, merge" , "ally" .)