A weapon in a right free-for-all (5)
I believe the answer is:
arrow
'a weapon' is the definition.
(I know that arrow is a weapon)
'a right free-for-all' is the wordplay.
'a right' becomes 'ar' (I've seen this in other clues).
'free-for-all' becomes 'row' (I can't justify this - if you can you should give a lot more credence to this answer).
'ar'+'row'='ARROW'
'in' is the link.
Can you help me to learn more?
(Other definitions for arrow that I've seen before include "Direction pointer" , "Missile of the archer" , "Archery projectile" , "Indicator; missile" , "Weapon projectile" .)