Section of part is tough for performer (6)
I believe the answer is:
artist
'performer' is the definition.
(eg a musician)
'section of part is tough' is the wordplay.
'section of' indicates the answer is hidden within the clue.
'ARTIST' is hidden within 'part is tough'.
'for' acts as a link.
(Other definitions for artist that I've seen before include "A painter, sculptor or other creative person" , "Creative individual" , "Rousseau perhaps" , "Model employer, perhaps" , "eg Monet" .)