Dispute line (3)
I believe the answer is:
row
I believe this clue is a double definition.
'dispute' is the first definition.
(row is a kind of dispute)
'line' is the second definition.
(a row or line of things)
(Other definitions for row that I've seen before include "Disagreement" , "Use an oar" , "Propel boat with manual aids" , "One of the ranks" , "falling out" .)