Lacquer (7)
I believe the answer is:
varnish
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">lacquer</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 varnish that I've seen before include "Hard, lustrous, transparent finish to a surface" , "Shiny transparent coating used on wood" , "'Hard, transparent finish to a surface (7)'" , "Glossy stain" , "Apply hard shiny stuff to wooden surface" .)