Lady on rock, evermore lethally emitting intoning, primarily? (7)

I believe the answer is:

lorelei

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'lady on rock evermore lethally emitting intoning primarily?' is the definition.
I know that 'rock' relates to this answer.

'lady on rock evermore lethally emitting intoning primarily?' is the wordplay.
'primarily?' indicates taking the first letters (I've seen 'primarily' mean this).
The initial letters of 'lady on rock evermore lethally emitting intoning' is 'LORELEI'.

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(Other definitions for lorelei that I've seen before include "Rhine Rock where sirens once dwelled" , "Fatal attraction" , "Rhine rock of siren legend" , "Rock-dwelling siren" , "A Rhine maiden" .)

I've seen this clue in The Everyman puzzle in The Observer.

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