Piccadilly hotel (4)
I believe the answer is:
ritz
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">piccadilly hotel</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 ritz that I've seen before include "Luxurious hotel" , "Swiss hotelier, who founded an international chain, d. 1918" , "(Expensive) London hotel" , "Ostentatious luxury" , "Piccadilly hotel" .)