New quarrel perhaps for reactionary (6)
I believe the answer is:
narrow
'reactionary' is the definition.
(reactionary can mean conservative or narrow-minded)
'new quarrel perhaps' is the wordplay.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'quarrel perhaps' becomes 'arrow' (quarrel is a kind of arrow).
'n'+'arrow'='NARROW'
'for' acts as a link.
(Other definitions for narrow that I've seen before include "Strait, tight" , "Bigoted opinion" , "Limited in scope; not wide" , "Fine" , "Restricted in width." .)