Teharoth, "Clean Things":
This title is used euphemistically for "unclean things":
(1) Kelim, "Vessels" (Lev 6:20 f; 11:32 ff; Num 19:14 ff; 31:20 ff).
(2) 'Oholoth, "Tents," the impurity originating with a corpse or a part of it (compare Num 19:14).
(3) Negha`im, "Leprosy" (Lev 13-14).
(4) Parah, "Red Heifer"; its ashes used for the purpose of purification (Num 19:2 ff).
(5) Teharoth, "Clean Things," euphemistically for defilements.
(6) Mikwa'oth, "Diving-Baths" (Lev 15:12; Num 31:33; Lev 14:8; 15:5 ff; compare Mark 7:4).
(7) Niddah, "The Menstruous" (Lev 15:19 ff; 12).
(8) Makhshirin, "Preparers," or Mashqin, "Fluids" (first word of the treatise). Seven liquids (wine, honey, oil, milk, dew, blood, water) which tend to cause grain, etc., to become defiled (compare Lev 11:34,37 f) .
(9) Zabhim, "Persons Having an Issue," flux (Lev 15).
(10) Tebhul yom, "A Person Who Has Taken the Ritual Bath during the Day," and is unclean until sunset (Lev 15:5; 22:6 f).
(11) Yadhayim, "Hands," the ritual impurity of hands and their purification (compare Matt 15:2,20; Mark 7:22 ff).
(12) `Uqtsin, "Stalks," the conveyance of ritual impurity by means of the stalks and hulls of plants.