Form a union with James? (4)
I believe the answer is:
bond
'james?' is the definition.
(James Bond is a fictional spy)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for bond that I've seen before include "Certificate of debt" , "Affinity" , "Tie - debenture" , "one licensed to kill" , "Written promise" .)