Rock singer? (7)
I believe this is a double definition.
'rock' is the first definition.
(rock by the River Rhine in Germany)
'singer?' is the second definition.
(I've seen this before)
(Other definitions for lorelei that I've seen before include "A Rhine maiden" , "Fatal nymph of the Rhine" , "enchantress" , "Twenty down siren nymph; lie role (anag.)" , "Jerk" .)
'rock singer?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for siren that I've seen before include "Risen like Lorelei" , "Temptress - warning device" , "Dangerously alluring woman" , "Bewitching singer" , "Loud whistle or sailors' enchantress" .)