A fancied flier (3)

I believe the answer is:

roc

I'm a little stuck... Click here to teach me more about this clue!

'flier' is the definition.
(I have seen 'Legendary flier' mean 'roc' so perhaps 'flier' could also mean 'roc')

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for roc that I've seen before include "Sinbad's huge bird" , "Legendary air carrier" , "Vast legendary bird" , "Sinbad's giant bird" , "Legendary flier" .)

I've seen this clue in the Evening Standard.

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