Dirtiness, filthiness (7)
I believe the answer is:
squalor
I believe this is a double definition.
'dirtiness' is the first definition.
(I know that squalor is a type of dirtiness)
'filthiness' is the second definition.
(I've seen this before)
(Other definitions for squalor that I've seen before include "Sleaziness, mean poverty" , "Dirt and untidiness" , "sleaze" , "Extremely dirty state" , "What could be filthy" .)