Follow with a brush (4)
I believe the answer is:
tail
This clue is a double definition.
'follow' is the first definition.
(thesaurus)
'a brush' is the second definition.
(thesaurus)
'with' acts as a link.
(Other definitions for tail that I've seen before include "part of coat" , "Animal's elongated appendage" , "Trail (behind comet)" , "Hindmost part" , "bum" .)