Anteroom (5)
I believe the answer is:
foyer
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">anteroom</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for foyer that I've seen before include "Theatre public area" , "Reception lobby" , "Hotel entrance hall" , "Entrance hallway" , "Vestibule" .)