Unwanted plant (4)
I believe the answer is:
weed
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">unwanted plant</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 weed that I've seen before include "Made water" , "Ineffectual person" , "pot" , "dope" , "Useless plant - useless person" .)