(indeel.) surely, undoubtedly (ekaṃsavacanaṃ Snp-a.348) usually in negative (& interrog. sentences as na jātu, not at all, never (cp. also sādhu) mā jātu Vin.ii.203; Snp.152, Snp.348 (no ce hi jātu); Ja.i.293 Ja.i.374; Ja.iv.261; Ja.v.503. Na jātucca at Ja.vi.60 is apparently for na jātu ca.

Vedic jātu, particle of affirmation. Perhaps for jānātu one would know, cp. Gr. ο ̓ϊμαι, Lat. credo P. maññe. But BR. and Fausböll make it a contraction of jāyatu “it might happen.” Neither of these derivations is satisfactory