Degree of difference (8)
I believe the answer is:
contrast
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">degree of difference</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for contrast that I've seen before include "Something completely different" , "Unlikeness shown by comparison" , "No tracts by way of difference" , "Compare to show differences" , "Disparity" .)