Hero's lover (7)
I believe the answer is:
leander
'hero's lover' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for leander that I've seen before include "He swam for love" , "In Greek legend, lover of Hero who drowned in the Hellespont" , "Learned Greek lover who swam Hellespont to meet Hero" , "Ill-fated lover" , "Hero-worshipper" .)