Play a leading role (4)
I believe the answer is:
star
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">play a leading role</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for star that I've seen before include "Ball of fire" , "Pointed shape" , "Red Dwarf?" , "A heavenly body or film favourite" , "Point of light in the heavens" .)