Individual non-member of a union (6,6)
I believe the answer is:
'a union' is the definition.
I know nothing about this answer so I can't tell whether this works.
'individual non-member' is the wordplay.
'individual' becomes 'single'.
'non member' becomes 'person' (I can't explain this - if you can you should give a lot more credence to this answer).
'of' acts as a link.
Can you help me to learn more?