Surface shine (5)
I believe the answer is:
gloss
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">surface shine</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 gloss that I've seen before include "marginal note" , "High shine" , "Sheen - paint" , "Show" , "Surface shine" .)