indeclinable

1. beginning, undertaking etc., in cpd. -vatthu occasion for making an effort, concern, duty, obligation DN.iii.256 = AN.iv.334 (eight such occasions enumerated).
2. (prep. with acc.) lit. beginning with, taking (into consideration), referring to, concerning, with reference to, about DN.i.180; AN.ii.27; Iti.103 (senāsanaṃ ā.); Snp.972 (upekhaṃ; variant reading ārambha C. uppādetvā); Pv.4.1 (pubbe pete ā.); Dhp-a.i.3; Dhp-a.ii.37; Pv-a.3 (seṭṭhiputta-petaṃ ā.), Pv-a.16, and passim.

ger. of ārabhati² in abs. function; cp. Sk. ārabhya meaning since, from