Persist as a winged beast? (6)
I believe the answer is:
dragon
'beast?' is the definition.
(thesaurus)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for dragon that I've seen before include "Racing yacht" , "See 7" , "Fail tediously to conclude" , "St George slew one" , "Formidable woman" .)