### Clue: One previously learning the French for "siren"' (7)
### Answer: LORELEI 
 ### Explanation: Definition: siren
As in a couple of other clues the wordplay is a bit contorted, but I think it works: One (I) with, previously, LORE (learning) + LE (the French). A change from "rock singer" as a clue for Lorelei, anyway