Sit for artist (4)
I believe the answer is:
pose
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sit for artist</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 pose that I've seen before include "Strike an attitude as for photo" , "Pretence" , "Attitude struck" , "Pretend to be somebody else" , "Affectation" .)