CGS unit of work or energy (3)
I believe the answer is:
erg
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">cgs unit of work</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">energy</span>' is the second definition.<br/ ><br/ ></span>
(Other definitions for erg that I've seen before include "shifting sand" , "Unit of work or energy" , "Unit of work; dunes area" , "Amount of work" , "What's used to record work" .)