Greek I (4)
I believe the answer is:
iota
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">greek i</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for iota that I've seen before include "Greek letter; tiny amount" , "Jot, particle" , "Ninth letter of Greek alphabet, small amount" , "The smallest possible amount, or the Greek i" , "Smidgen" .)