Burro, for instance (3)
I believe the answer is:
ass
'burro for instance' is the definition.
(I know that burro is a type of Equus asinus)
This is the entire clue.
(Other definitions for ass that I've seen before include "oaf" , "Horse-type animal" , "Idiot; animal" , "Long-eared animal" , "Jennet" .)