Units of electric current (4)
I believe the answer is:
amps
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">units of electric current</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 amps that I've seen before include "concert gear" , "'Units of electric current, in short (4)'" , "Current measures" , "Spam (anag)" , "Units of electrical power" .)