Royal topper (5)
I believe the answer is:
crown
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">royal topper</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for crown that I've seen before include "Coin; royal headgear" , "Hit on the head (informal)" , "Symbol of monarchy" , "piece of tooth" , "The sovereign" .)