The Collaborative International Dictionary of English v.0.48:
Filth \Filth\ (f[i^]lth), n. [OE. filthe, ful[eth]e, AS.
f[=y]l[eth], fr. f[=u]l foul; akin to OHG. f[=u]lida. See
Foul, and cf. File.]
1. Foul matter; anything that soils or defiles; dirt;
2. Anything that sullies or defiles the moral character;
To purify the soul from the dross and filth of
sensual delights. --Tillotson.
Filth disease (Med.), a disease supposed to be due to
pollution of the soil or water.