Burden of responsibility (4)
I believe the answer is:
onus
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">burden of responsibility</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 onus that I've seen before include "Capulet opponent (R&J)" , "Responsibilty" , "Liability" , "Encumbrance" , "Weight of responsibility" .)