Returning, achieved very good times (5)
I believe the answer is:
tempi
'times' is the definition.
(tempo is a kind of time)
'returning achieved very good' is the wordplay.
'returning' shows that the letters should be reversed in order.
'achieved' becomes 'met' (I've seen this in another clue).
'very good' becomes 'pi' (I've seen this in other clues).
'met' reversed gives 'tem'.
'tem'+'pi'='TEMPI'
(Other definitions for tempi that I've seen before include "Beats" , "Speeds, rhythms of musical pieces" , "Speeds (music)" , "Speeds for musicians" , "Times" .)