Deadly nightshade (10)
I believe the answer is:
belladonna
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">deadly nightshade</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for belladonna that I've seen before include "brought a sparkle to the eye" , "Drug made from deadly nightshade" , "plant" , "Boy in Lebanon destroyed" , "Deadly nightshade or atropine" .)