Approach argument (3-2)
I believe the answer is:
run-in
This clue is a double definition.
'approach' is the first definition.
(I've seen this before)
'argument' is the second definition.
(I know that run-in is a type of argument)
(Other definitions for run-in that I've seen before include "Home straight" , "Quarrel" , "Dispute" , "Fight, disagreement" , "Matches late in season" .)