Peer's son showing off to Sally (8)
I believe the answer is:
response
'sally' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'peer's son showing off' is the wordplay.
'peer's son' can be anagrammed to 'RESPONSE'.
However, I'm not sure how the anagram is indicated.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for response that I've seen before include "Reply, rejoinder" , "'Answer, reply (8)'" , "Reaction, reply" , "Acknowledgement" , "Rejoinder, retort" .)