Grime, filth (4)
I believe the answer is:
dirt
I believe this is a double definition.
'grime' is the first definition.
(synonyms)
'filth' is the second definition.
(I know that filth can be written as dirt)
(Other definitions for dirt that I've seen before include "Loose soil; filth" , "'Mud, dust or grime (4)'" , "Grime - or controversial retention tax" , "Scandalous information" , "Scandalous info; earth" .)