One way to stop a fight? (4)

I believe the answer is:
kayo
(Other definitions for kayo that I've seen before include "Knock out in boxing" , "Decisive end to a fight?" , "Decisive blow (in boxing)" , "Conclusion of a bout" , "Knockout" .)
I believe the answer is:
kayo
(Other definitions for kayo that I've seen before include "Knock out in boxing" , "Decisive end to a fight?" , "Decisive blow (in boxing)" , "Conclusion of a bout" , "Knockout" .)