Of the least possible (7)
I believe the answer is:
minimal
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">of the least possible</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for minimal that I've seen before include "Least possible; negligible" , "Of a smallest amount" , "barely worth considering" , "Very little" , "Of the least possible size" .)