Capital of Spain (6)
I believe the answer is:
madrid
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">capital of spain</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for madrid that I've seen before include "Capital of Spain since 1561" , "Spanish capital" , "European capital city" , "City with the Prado national art gallery" , "Spanish city" .)