Legendary Rhine siren (7)
I believe the answer is:
lorelei
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">legendary rhine siren</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for lorelei that I've seen before include "High rock in the Rhine gorge" , "Rhine Rock where siren lived" , "alluring female" , "Fatal attraction" , "Great Rock on the Rhine where sirens lived in legend" .)