Horse in shock couple of rounds - it’s trailing (9)
I believe the answer is:
appaloosa
'horse' is the definition.
(Appaloosa is an example)
'shock couple of rounds it's trailing' is the wordplay.
'shock' becomes 'appal' (synonyms).
'couple of rounds' becomes 'OO' (round can mean a round object like an O).
'it' becomes 'sa' (SA can mean sex appeal, as in 'it').
'trailing' is a charade indicator (letters next to each other).
'appal'+'oo'+'sa'='APPALOOSA'
'in' acts as a link.
(Another definition for appaloosa that I've seen is " Horse breed, with spotted rump".)