Hangs about - it's a grind (5)
I believe the answer is:
gnash
'a grind' is the definition.
(thesaurus)
'hangs about' is the wordplay.
'about' indicates an anagram.
'hangs' is an anagram of 'GNASH'.
'it's' acts as a link.
(Other definitions for gnash that I've seen before include "grinding action" , "Hangs (anag.)" , "Grind away" , "Grind (teeth) together" , "grate" .)