Small sum (4)
I believe the answer is:
mite
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">small sum</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 mite that I've seen before include "The widow's small offering" , "Minute creature" , "Tiny arachnid, person or amount of money" , "Minute arachnid" , "Microscopic creature" .)