Racecourse near Windsor (5)
I believe the answer is:
ascot
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">racecourse near windsor</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 ascot that I've seen before include "sporting event" , "Necktie with wide square ends" , "Type of necktie" , "Racecourse near Windsor" , "Racecourse, home to the Gold Cup since 1807" .)