Carnival city (3)
I believe the answer is:
rio
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">carnival city</span>' is the definition.<br/ ><span class="explanation-format__explanation">(Rio de Janeiro is famous for its carnival)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for rio that I've seen before include "Brazilian city and port" , "Port, -- de Janeiro" , "... Grande, ... de Janeiro" , "Location of next Olympic Games, in short" , "Spanish word for river" .)