A drive to become diversified (6)
I believe the answer is:
varied
'diversified' is the definition.
(varying is a kind of diversifying)
'a drive to become' is the wordplay.
'to become' indicates an anagram.
'a'+'drive'='adrive'
'adrive' anagrammed gives 'VARIED'.
(Other definitions for varied that I've seen before include "Differing" , "Wide-ranging" , "Miscellaneous" , "Changed" , "Diversified; modified" .)