Look happy (5)
I believe the answer is:
smile
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">look happy</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 smile that I've seen before include "Pleasant expression" , "Grin" , "Friendly facial gesture" , "Indicate pleasure with lips movement" , "Show amusement or pleasure" .)