Start being different (5)
I believe the answer is:
begin
'start' is the definition.
(I know that start can be written as begin)
'being different' is the wordplay.
'different' indicates an anagram (letters placed in a different order).
'being' with letters rearranged gives 'BEGIN'.
(Other definitions for begin that I've seen before include "Commence" , "Clandestine, furtive" , "Make a start" , "Found" , "Israeli prime minister and Nobel Peace Prize winner, d. 1992" .)