Hang dog (5)
I believe the answer is:
trail
This clue is a double definition.
'hang' is the first definition.
(thesaurus)
'dog' is the second definition.
(both can mean to follow)
(Other definitions for trail that I've seen before include "Beaten path; be in losing position" , "Track, route" , "Rough path" , "Drag behind" , "Fall behind" .)