Hog sound (4)
I believe the answer is:
oink
'hog sound' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for oink that I've seen before include "what we hear from Berkshire?" , "Noise a pig makes" , "Piggish noise" , "What farmer hears" , "behave like a pig" .)