The most common and most likely answer to this crossword clue is the 6 letter word ISOLDE
I've seen this crossword clue in The Daily Telegraph
I
S
O
L
D
E
More clues leading to the result ISOLDE
- Tristan’s lover, one deceived by English
- Legendary royal drug-dealer’s confession?
- Legendary princess some feared losing has returned
- Tragic part of a drug dealer’s confession?
- Princess lives with elderly European
- Princess is no spring chicken, last in line
- Princess is getting on plane at last
- Irish leader disposed of drug for operatic heroine
- Princess is no spring chicken – last in line
- Tragic heroine features in this old epic
Buddy explains!

The straight part
We know that "Lover" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lover = isolde.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.