Siren (7)
I believe the answer is:
lorelei
'siren' is the definition.
(I know that Lorelei is a siren)
This is all the clue.
(Other definitions for lorelei that I've seen before include "A dangerously attractive lady" , "Rhine Rock where sirens once dwelled" , "Twenty down siren nymph; lie role (anag.)" , "Legendary siren luring Rhine boatmen to destruction" , "Rhine rock of siren legend" .)