Dog end (4)
I believe the answer is:
tail
I believe this is a double definition.
'dog' is the first definition.
(synonyms)
'end' is the second definition.
(I know that tail is a type of end)
(Other definitions for tail that I've seen before include "Flexible part that extends from an animal's rear" , "Follow - dog" , "Elongated appendage of an animal" , "bum" , "that can be cast by a lizard" .)