New weapon, limited in scope (6)
I believe the answer is:
narrow
'limited in scope' is the definition.
(I've seen this before)
'new weapon' is the wordplay.
'new' becomes 'n'.
'weapon' becomes 'arrow' (arrow is a kind of weapon).
'n'+'arrow'='NARROW'
(Other definitions for narrow that I've seen before include "Meagre, confined" , "Strict" , "Sort of boat, escape, gauge or squeak" , "Slender - spare" , "Bigoted opinion" .)