Messy dresser (4)
I believe the answer is:
'messy dresser' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for slob that I've seen before include "Fat, idle type" , "Boor" , "Slovenly person (colloq.)" , "Sort of ice" , "Slovenly layabout" .)