Least amount possible (7)
I believe the answer is:
minimum
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">least amount 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 minimum that I've seen before include "Nadir" , "Smallest possible quantity" , "Least recorded value" , "Least possible quantity" , "Lowest point" .)