The race's over for such professionals (8)
I believe the answer is:
teachers
'professionals' is the definition.
(teacher is a kind of professional)
'the race's over' is the wordplay.
'over' indicates an anagram.
'the'+'races'='theraces'
'theraces' is an anagram of 'TEACHERS'.
'for such' is the link.
(Other definitions for teachers that I've seen before include "Pedagogues" , "Coaches" , "Instructors" , "Instuctors" , "They impart knowledge" .)