1.  Foul matter; anything that soils or defiles; dirt; nastiness. [1913 Webster]

2.  Anything that sullies or defiles the moral character; corruption; pollution. [1913 Webster]
"To purify the soul from the dross and filth of sensual delights." [1913 Webster]

filth, n.
1 repugnant or extreme dirt.
2 vileness, corruption, obscenity.
3 foul or obscene language.
4 (prec. by the) sl. the police.

Etymology:
OE fylth (as FOUL, -TH(2))

N  uncleanness, impurity, immundity, immundicity, impurity, defilement, contamination, defoedation, soilure, soiliness, abomination, leaven, taint, tainture, fetor, decay, putrescence, putrefaction, corruption, mold, must, mildew, dry rot, mucor, rubigo, slovenry, slovenliness, squalor, dowdy, drab, slut, malkin, slattern, sloven, slammerkin, slammock, slummock, scrub, draggle-tail, mudlark, dust-man, sweep, beast, dirt, filth, soil, slop, dust, cobweb, flue, smoke, soot, smudge, smut, grit, grime, raff, sossle, sozzle, sordes, dregs, grounds, lees, argol, sediment, settlement heeltap, dross, drossiness, mother, precipitate, scoriae, ashes, cinders, recrement, slag, scum, froth, hogwash, ditchwater, dishwater, bilgewater, rinsings, cheeseparings, sweepings, offscourings, outscourings, off scum, caput mortuum, residuum, sprue, fecula, clinker, draff, scurf, scurfiness, exuviae, morphea, fur, furfur, dandruff, tartar, riffraff, vermin, louse, flea, bug, chinch, mud, mire, quagmire, alluvium, silt, sludge, slime, slush, slosh, sposh, spawn, offal, gurry, lientery, garbage, carrion, excreta, slough, peccant humor, pus, matter, suppuration, lienteria, faeces, feces, excrement, ordure, dung, crap, shit, sewage, sewerage, muck, coprolite, guano, manure, compost, dunghill, colluvies, mixen, midden, bog, laystall, sink, privy, jakes, toilet, john, head, cess, cesspool, sump, sough, cloaca, latrines, drain, sewer, common sewer, Cloacina, dust hole, sty, pigsty, lair, den, Augean stable, sink of corruption, slum, rookery, dirty, filthy, grimy, unclean, impure, soiled, not to be handled with kid gloves, dusty, snuffy, smutty, sooty, smoky, thick, turbid, dreggy, slimy, mussy, slovenly, untidy, messy, uncleanly, unkempt, sluttish, dowdy, draggle-tailed, uncombed, unscoured, unswept, unwiped, unwashed, unstrained, unpurified, squalid, lutose, slammocky, slummocky, sozzly, nasty, coarse, foul, offensive, abominable, beastly, reeky, reechy, fetid, decayed, moldy, musty, mildewed, rusty, moth-eaten, mucid, rancid, weak, bad, gone bad, etercoral, lentiginous, touched, fusty, effete, reasty, rotten, corrupt, tainted, high, flyblown, maggoty, putrid, putrefactive, putrescent, putrefied, saprogenic, saprogenous, purulent, carious, peccant, fecal, feculent, stercoraceous, excrementitious, scurfy, scurvy, impetiginous, gory, bloody, rotting, rotten as a pear, rotten as cheese, crapulous, gross, fimetarious, fimicolous, they that touch pitch will be defiled.