Get a man to become a tycoon (7)
I believe the answer is:
magnate
'a tycoon' is the definition.
(I know that tycoon can be written as magnate)
'get a man to become' is the wordplay.
'to become' indicates an anagram.
'get'+'a'+'man'='getaman'
'getaman' is an anagram of 'MAGNATE'.
(Other definitions for magnate that I've seen before include "Wealthy figure" , "Wealthy or powerful businessman" , "Mogul" , "Fellow with a lot of money" , "Baron" .)