Sportswriter Berkow (3)
I believe the answer is:
ira
'sportswriter berkow' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ira that I've seen before include "Brother of George Gershwin" , "George 13 down's brother" , "Militant republicans" , "Illegal organisation, in short" , "terrorists" .)