Alexander Dyce, A General Glossary to Shakespeare's Works

filth used as a term of reproach and contempt: “Filth as thou art,” THE TEMPEST, i. 2. 346 ; “Filth, thou liest!” OTHELLO, v. 2. 234 ; “To general filths Convert o' the instant, green virginity!” TIMON OF ATHENS, iv. 1. 6 ; “Filths savour but themselves,” KING LEAR, iv. 2. 39. In the third of these passages Steevens explains general filths by “common sewers;” but surely the meaning is “common whores;” and so in the second passage “Filth” seems from Iago's preceding speech to be equivalent to “whore.” (Compare Greene's Notable Discouery of Coosnage, etc., 1592: “To him will some common filth [that neuer knew loue] faine an ardent and honest affection,” Sig. c 4. )