SQUALID
flyblown, squalid, sordid
(adjective) 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”
seamy, seedy, sleazy, sordid, squalid
(adjective) 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”
Source: WordNet® 3.1
Etymology 1
Adjective
squalid (comparative squalider, )
Extremely dirty and unpleasant.
Showing a contemptible lack of moral standards.
Etymology 2
Noun
squalid (plural squalids)
(zoology) Any member of the family Squalidae of dogfish sharks.
Source: Wiktionary
Squal"id, a. Etym: [L. squalidus, fr. squalere to be foul or filthy.]
Definition: 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: Webster’s Unabridged Dictionary 1913 Edition