The capital of Portugal (6)
I believe the answer is:
lisbon
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">the capital of portugal</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for lisbon that I've seen before include "Capital of Portugal" , "Capital city and Treaty" , "Capital city on the Tagus" , "Portuguese capital" , "European capital" .)