Misplaced cheers or a fast nag (9)
I believe the answer is:
racehorse
'fast nag' is the definition.
The definition and answer can be both animals as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'misplaced cheers or a' is the wordplay.
'misplaced' indicates anagramming the letters.
'cheers'+'or'+'a'='cheersora'
'cheersora' is an anagram of 'RACEHORSE'.
Can you help me to learn more?
(Other definitions for racehorse that I've seen before include "Animal" , "runner" , "Arab possibly" , "jumper?" , "Competitive beast" .)