indeclinable
Atho (indeclinable) [Sanskrit atho, atha + u] copulative and adversative particle: and, also, and further, likewise, nay S I 106; Snp 43, 155, 647; Dhp 151, 234, 423; Ja I 83; II 185; IV 495; It 106; Khp VIII 7; Pv IV 3 15 ; Pv-a 251 (atho ti nipātamattaṃ avadhāraṇ-atthe vā). Also combined with other particles, like atho pi Snp 222, 537, 985; Pv II 3 20 ; Pj I 166.
and also; likewise; and yet, even then
(ind, ind, from atha) and then; or; after that; because of then, and also Construction: atha + u > atho