Thrilla in Manila boxer (3)
I believe the answer is:
ali
'thrilla in manila boxer' 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 "Mohammad . . ., . . . Hewson" , "Muhammad's son-in-law" , "Muslim name" , "Lepidopterous floater, apian stinger, d. 2016" , "Muhammad - - , legendary boxer" .)