Follow the rear (4)
I believe the answer is:
tail
I believe this is a double definition.
'follow' is the first definition.
(thesaurus)
'the rear' is the second definition.
(tail is a kind of rear)
(Other definitions for tail that I've seen before include "that can be cast by a lizard" , "Comet's luminous trail" , "Follow - train" , "Follow - rear part of aeroplane" , "Elongated posterior part of an animal" .)