Crowd scene actor (5)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">crowd scene actor</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 extra that I've seen before include "Additional - run - actor - newspaper edition" , "Not a standard item" , "Bit actor in movie's crowd scenes" , "Additional - bye" , "Possibly overthrow" .)