Monkshood (7)
I believe the answer is:
aconite
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">monkshood</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for aconite that I've seen before include "potential killer" , "Yellow-flowered plant" , "Poisonous flowering plant" , "Flower, for example monkshood or wolfsbane" , "Spring flower - poison" .)