Isolate (10)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">isolate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(quarantining is a kind of isolating)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for quarantine that I've seen before include "Period of isolation to prevent spread of disease" , "Isolate (to prevent spread of disease)" , "separate from others" , "solitary confinement" , "State of isolation" .)