Sound from a sty (5)
'sound from a sty' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for oink that I've seen before include "Pig's noise" , "it might be in a pen one hears" , "Beastly sound" , "Beastly noise" , "Cartoon sound of pig" .)
(Other definitions for snort that I've seen before include "Force air out of the nose" , "Take cocaine (sl.)" , "drink, a quickie" , "Rough nasal sound of disgust or anger" , "Take illegal drug" .)