What is left (7)
I believe the answer is:
residue
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">what is left</span>' is the definition.<br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for residue that I've seen before include "Leftovers" , "Part remaining" , "rest" , "Deposit" , "grounds" .)