Be author of western ceremony (5)
I believe the answer is:
write
'be author' is the definition.
(I've seen this in another clue)
'western ceremony' is the wordplay.
'western' becomes 'w'.
'ceremony' becomes 'rite' (rite is a kind of ceremony).
'w'+'rite'='WRITE'
'of' acts as a link.
(Other definitions for write that I've seen before include "Compose; correspond" , "Put pen to paper" , "Use a pen/pencil" , "Compose (music)" , "Produce text" .)