Untidy person (6)
I believe the answer is:
scruff
'untidy person' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for scruff that I've seen before include "Part of neck" , "Tramp" , "Untidy person (slang); nape" , "Back of the neck; untidy person" , "Untidy person - nape of neck" .)