Unit of electric potential (4)
I believe the answer is:
volt
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">unit of electric potential</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 "Electrical SI unit named after a pioneering Italian physicist, d. 1827" , "Unit of electric force" , "A measure of electricity" , "Electricity unit" , "Electrical unit of measurement" .)