Academic turning up for affirmative action (3)
I believe the answer is:
nod
'affirmative action' is the definition.
(I've seen this in another clue)
'academic turning up' is the wordplay.
'academic' becomes 'don' (type of academic - especially at Oxbridge).
'turning up' shows that the letters should be reversed in order.
'don' backwards is 'NOD'.
'for' acts as a link.
(Other definitions for nod that I've seen before include "OK" , "sleepy land" , "Signal with the head" , "Careless mistake" , "Signify consent" .)