Call to attention? (4)
I believe the answer is:
psst
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">call to attention?</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for psst that I've seen before include "Call to attract attention" , "Sibilant sound made to attract attention" , "Sibilant interjection to call attention" , "Interjection to draw attention" , "Quiet call for attention" .)