Abbot nods now and then to form a connection (4)
I believe the answer is:
bond
'form a connection' is the definition.
(I've seen this in another clue)
'abbot nods now and then' is the wordplay.
'now and then' means one should take alternating letters (letters taken on a regular basis, now and then).
'abbot'+'nods'='abbotnods'
The alternating letters of 'abbotnods' are 'BOND'.
'to' acts as a link.
(Other definitions for bond that I've seen before include "Link, connection" , "Fellow feeling" , "Unite" , "Tie - 007" , "Written promise" .)