Weight of an empty container
I believe the answer is:
tare
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">weight of an empty container</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for tare that I've seen before include "Vessel's weight" , "Rate a vetch" , "Vehicle's empty weight" , "Vehicle weight minus fuel and load" , "Biblical weed" .)