Capital city of Azerbaijan (4)
I believe the answer is:
baku
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">capital city of azerbaijan</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 baku that I've seen before include "Capital city of Azerbaijan" , "Capital of Azerbaijan on shore of Caspian Sea" , "Caspian Sea port" , "Azerbaijan's capital" .)