Disruption (8)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">disruption</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 upheaval that I've seen before include "Disruptive disturbance" , "At university, books are taken in to cure" , "Disorder, turmoil" , "Violent or sudden change or disruption" , "Turbulence" .)
(Other definitions for unrest that I've seen before include "State of agitation" , "Disturbance or dissatisfaction" , "revolutionary state" , "'Disturbance, agitation (6)'" , "State of uneasiness" .)