Be seated (3)
I believe the answer is:
sit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">be seated</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 sit that I've seen before include "Serve (on jury)" , "Rest on one's haunches" , "Use a chair" , "Take a pew, an exam" , "Pose for painter" .)