SI unit of electromotive force (4)
I believe the answer is:
volt
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">si unit of electromotive force</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 volt that I've seen before include "Electricity unit" , "Unit of electric potential difference" , "little force" , "Unit of electric force" , "Unit of electrical potential" .)