Tare (5)
I believe the answer is:
vetch
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tare</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for vetch that I've seen before include "Climbing plant of the pea family, cultivated as fodder" , "Climber" , "Purple climbing plant" , "Wild plant with purple flowers" , "Leguminous plant" .)