Possibly unites, but here separates (6)
I believe the answer is:
unties
'here separates' is the definition.
The answer and definition can be both to do with contact as well as being verbs in their -s form.
Perhaps there's an association between them I don't understand?
'possibly unites' is the wordplay.
'possibly' indicates anagramming the letters.
'unites' with letters rearranged gives 'UNTIES'.
'but' acts as a link.
Can you help me to learn more?
(Other definitions for unties that I've seen before include "Opens knot to release" , "Undoes, loosens a knot" , "Loosens laces" , "Undoes, a knot perhaps" .)