Ruthlessly competitive (3-3-3)
I believe the answer is:
dog-eat-dog
'ruthlessly competitive' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dog-eat-dog that I've seen before include "Ruthless competition - self-interest" , "Internecine competition" , "Ruthless competition of canine cannibals" , "Condition of savage self-interest" , "Savage self concern" .)