The Collaborative International Dictionary of English v.0.48:

Squalor \Squa"lor\ (skw[=a]"l[^o]r), n. [L., fr. squalere to be
   foul or filthy.]
   Squalidness; foulness; filthiness; squalidity.
   [1913 Webster]

         The heterogeneous indigent multitude, everywhere
         wearing nearly the same aspect of squalor. --I. Taylor.
   [1913 Webster]

         To bring this sort of squalor among the upper classes.
                                                  --Dickens.
   [1913 Webster]

WordNet (r) 3.0 (2006):

squalor
    n 1: sordid dirtiness [syn: sordidness, squalor,
         squalidness]