Ring legend (3)
I believe the answer is:
'ring legend' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ali that I've seen before include "Lepidopterous floater, apian stinger, d. 2016" , "Muslim name" , "US heavyweight boxer" , "Muhammad's son-in-law" , "Former boxing champion" .)