Is a good dog (5)
I believe the answer is:
obeys
'is a good dog' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for obeys that I've seen before include "Carries out orders" , "Submits to authority" , "Carries out (instruction)" , "Does what one is told" , "Complies with orders" .)