Definitive (7)
I believe the answer is:
classic
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">definitive</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 classic that I've seen before include "Artistic work of lasting excellence" , "Quintessential" , "Timeless-quality work; a race" , "Great piece of creative writing" , "Definitive; of recognised excellence" .)