Hackman perhaps provides some of his own make-up (4)
I believe the answer is:
gene
'hackman' is the definition.
(I've seen this in another clue)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for gene that I've seen before include "Basic unit of heredity" , "Hereditary DNA sequence" , "affects someone's make-up" , "Element of heredity" , "___ Kelly, star of Singin' In The Rain, d. 1996" .)