In action (2,4)
I believe the answer is:
at work
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">in action</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for at work that I've seen before include "Active" , "busy" , "Engaged in one's duties" .)