Differ in opinion (8)
I believe the answer is:
disagree
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">differ in opinion</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for disagree that I've seen before include "Quarrel" , "Differ in opinion" , "Beg to differ" , "Differ, argue" , "Take a different view" .)