Destined to be a rich man? (5)
I believe the answer is:
fated
'destined' is the definition.
('fated' can be a synonym of 'destined')
'a rich man?' is the wordplay.
'a rich' becomes 'fat'.
'man?' becomes 'ed' (**).
'fat'+'ed'='FATED'
'to be' is the link.
(Other definitions for fated that I've seen before include "Destined - inevitable" , "Suffering a lot" , "Predestined" , "Doomed or destined" , "Destined, foreordained (5)" .)