any alkaline substance, potash, lye. In combination with ūsa (salt earth) at SN.iii.131 (-gandha) AN.i.209
■ Used as a caustic Pv.iii.10#2; Sdhp.281. See also chārikā.

• -āpatacchika a means of torturing, in enumⁿ of var tortures (under vividha-kamma-kāranā kārenti) MN.i.87; AN.i.48 = AN.ii.122 = Cnd.604; Ja.vi.17 (variant reading ˚ṭicch˚; C. has āpatacchika, variant reading paṭicchaka); Vism.500; Mil.197 Both A & Nd have variant reading kharāpaṭicchaka;
• -odaka an alkaline solution Vism.264, Vism.420; Dhp-a.i.189; Pv-a.213 cp. khārodikā nadī (in Niraya) Sdhp.194.

Sk. kṣāra, pungent, saline, sharp to ksā, kṣāyati to burn, cp. Gr. ςηρός, dry; Lat. serenus, dry, clear seresco to dry