Coach put back row ... (4-2)
I believe the answer is:
bust-up
'row' is the definition.
(bust-up is a kind of row)
'coach put back' is the wordplay.
'coach' becomes 'bus' (synonyms).
'back' says the letters should be written in reverse.
'put' backwards is 'tup'.
'bus'+'tup'='BUST-UP'
(Other definitions for bust-up that I've seen before include "Argument finishing a relationship" , "Serious altercation" , "Serious quarrel/fight" , "Quarrel, possibly ending a friendship" , "disagreement" .)