Backing international's appeal (7)
I believe the answer is:
protest
'appeal' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe there's an association between them I don't understand?
'backing international's' is the wordplay.
'backing' becomes 'pro' (being pro something is backing or supporting it).
'international' becomes 'test' (as in a test match in cricket).
'pro'+'test'='PROTEST'
Can you help me to learn more?
(Other definitions for protest that I've seen before include "Public demonstration" , "Spotter of objection" , "Objection from potters" , "Showing support" , "Object loudly" .)