indeclinable disjunctive-adversative particle “or”, in direct questions DN.i.157; DN.ii.8; Snp.599, Snp.875, Snp.885; Ja.i.20, Ja.i.83; Vv-a.258 (= ādu); Pv-a.33, Pv-a.51; Mil.10
■ The first part of the question is often introduced with kiṃ, while udāhu follows in the second (disjunctive) part, e.g. kin nakkhattaṃ kīḷissasi udāhu bhatiṃ karissasi Vv-a.63; kiṃ amhehi saddhiṃ āgamissasi udāhu pacchā will you come with us or later? Dhp-a.ii.96: See under kiṃ
■ Often combined with other expletive particles, e.g. udāhu ve Snp.1075, Snp.1077; udāhu no Snp.347; eva… no udāhu (so… or not) DN.i.152; (ayaṃ) nu kho-udāhu (ayaṃ) is it (this)-(this) Vism.313.

uta + āho, cp. P. uda & aho and Sk. utāro