kind of harmful (nocturnal) demon, usually making the water its haunt and devouring men Thag.931; Snp.310 (Asura˚) Ja.i.127 (daka˚ = udaka˚), Ja.i.170 (id.); Ja.vi.469 (id.); Dhp-a.i.367 (˚pariggahita-pokkharaṇī); Dhp-a.iii.74 (udaka˚); Sdhp.189, Sdhp.313, Sdhp.366
■ f. rakkhasī Ja.iii.147 (r. pajā); Mhvs.12, Mhvs.45 (rudda˚, coming out of the ocean).

cp. Vedic rakṣa, either fr. rakṣ to injure, or more likely fr. rakṣ to protect or ward off (see details at Macdonell, Vedic Mythology pp. 162–164)