What's the point of a quarrel? (9)
I believe the answer is:
arrowhead
I believe this clue is a double definition.
'what's the point' is the first definition.
(arrowhead is a kind of point)
'a quarrel?' is the second definition.
(thesaurus)
'of' is the link.
(Other definitions for arrowhead that I've seen before include "Point to a weapon" , "Water plant" , "Tip of an old projectile" , "A suitable end for weapon" .)