Returning best trophy (3)
I believe the answer is:
pot
'trophy' is the definition.
(thesaurus)
'returning best' is the wordplay.
'returning' shows that the letters should be reversed in order.
'best' becomes 'top' ('top' can be similar in meaning to 'best').
'top' reversed gives 'POT'.
(Other definitions for pot that I've seen before include "...Karenina(Tolstoy)" , "'A watched . . . never boils'" , "Preserve; drug" , "Somewhere to go" , "Shoot; pan" .)