Approach; quarrel (3-2)
I believe the answer is:
run in
I believe this clue is a double definition.
'approach' is the first definition.
(I've seen this before)
'quarrel' is the second definition.
(I know that quarrel can be written as run-in)
(Other definitions for run in that I've seen before include "Approach; fight" , "Brush" , "drive new car" , "Carefully bring to full working order - arrest" , "Dispute" .)