The most common and most likely answer to this crossword clue is the 6 letter word FABLED
I've seen this crossword clue in The Times
F
A
B
L
E
D
More clues leading to the result FABLED
- Fantastic sort of light: legendary
- Legendary wizard acted as guide
- Legendary sailor ran off to the borders
- Mythical female sailor went first
- Perhaps like Sinbad, sailor put inside escaped
- Legendary sports chiefs close to club watch display
- Well-known ace was captain
- Groovy kind of light is legendary
- Legendary journalist replaced end of sticky-backed plastic.
- Legendary association of sportsmen exploited extortionately
Buddy explains!

The straight part
We know that "legendary" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case legendary = fabled.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.
What does FABLED mean?
FABLED verb- To compose fables; hence, to write or speak fiction; to write or utter what is not true.
- To make up; to devise, and speak of, as true or real; to tell of falsely; to recount in the form of a fable.
- Known only in fables; fictitious.
- Made known by fables; legendary, famed.