1. a great flood (= ogha), the sea or ocean (often as mah˚ cp. BSk. mahārṇava, e.g. Jtm.31#75) MN.i.134; SN.i.214 SN.iv.157 (mahā udak˚); Snp.173 (fig. for saṃsāra see Snp-a.214), Snp.183, Snp.184; Ja.i.119 (˚kucchi), Ja.i.227 (id.); Ja.v.159 (mah˚) Mhvs.5, Mhvs.60; Mhvs.19, Mhvs.16 (mah˚).
2. a stream, river Ja.iii.521; Ja.v.255.

Sk. arṇa & arṇava to; ṛ; ṛṇoti to move, Idg. *er to be in quick motion, cp. Gr. ο ̓́ρνυμι; Lat. orior Goth. rinnan = E. run; Ohg. runs, river, flow.