Ready for attack (3)
I believe the answer is:
fit
I believe this is a double definition.
'ready' is the first definition.
(thesaurus)
'attack' is the second definition.
(fit is a kind of attack)
'for' is the link.
(Other definitions for fit that I've seen before include "Of a suitable standard" , "Suitable; sudden attack" , "In good physical shape 93)" , "Healthy, exercised" , "Equip" .)