Heavyweight Mike ____ (5)
I believe the answer is:
tyson
'heavyweight mike' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tyson that I've seen before include "US world heavyweight boxing champion, b.1966 -- English fast bowler, d. 2015" , "Mike --, US boxer" , "American world heavyweight champion, b. 1966" , "Youngest ever undisputed world heavyweight boxing champion, b, 1966" , "Undisputed world heavyweight champion, 1987" .)