Units of resistance (4)
I believe the answer is:
ohms
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">units of resistance</span>' is the definition.<br/ ><span class="explanation-format__explanation">(units of electrical resistance)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ohms that I've seen before include "working for the monarchy?" , "Frank marking" , "lab units" , "degrees of resistance" , "Measure of resistance" .)