Source : Webster's Revised Unabridged Dictionary (1913)

Squalid \Squal"id\, a. [L. squalidus, fr. squalere to be foul or
   filthy.]
   Dirty through neglect; foul; filthy; extremely dirty.

         Uncomed his locks, and squalid his attrie. --Dryden.

         Those squalid dens, which are the reproach of large
         capitals.                                --Macaulay.

Source : WordNet®

squalid
     adj 1: morally degraded; "a seedy district"; "the seamy side of
            life"; "sleazy characters hanging around casinos";
            "sleazy storefronts with...dirt on the walls"- Seattle
            Weekly; "the sordid details of his orgies stank under
            his very nostrils"- James Joyce; "the squalid
            atmosphere of intrigue and betrayal" [syn: {seamy}, {seedy},
             {sleazy}, {sordid}]
     2: foul and run-down and repulsive; "a flyblown bar on the edge
        of town"; "a squalid overcrowded apartment in the poorest
        part of town"; "squalid living conditions"; "sordid
        shantytowns" [syn: {flyblown}, {sordid}]