All right to include fashionable, beastly sound (4)
I believe the answer is:
oink
'beastly sound' is the definition.
(I've seen this before)
'all right to include fashionable' is the wordplay.
'all right' becomes 'ok' (synonyms).
'to include' is an insertion indicator.
'fashionable' becomes 'in' (in can mean fashionable or trendy).
'ok' enclosing 'in' is 'OINK'.
(Other definitions for oink that I've seen before include "Beastly sound" , "Sound from a sty" , "Beastly noise" , "farmyard noise" , "Noise a pig makes" .)