Exemption for married Frenchman breaching international accord (8)
I believe the answer is:
immunity
'exemption' is the definition.
(synonyms)
'international accord' is the wordplay.
'international' becomes 'imm' (I am not sure about this - if you are sure you should believe this answer much more).
'accord' becomes 'unity' (I've seen this before).
'imm'+'unity'='IMMUNITY'
'for married frenchman breaching' is the link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for immunity that I've seen before include "Safety from prosecution, disease etc" , "I'm involved in mutiny, with special exemption (8)" , "Exemption; resistance" , "may be diplomatic" , "Exemption (from disease, prosecution etc)" .)