indeclinable

1. as conjunction: if; constructed either with pres. indic., as: Snp.189; “yadi bodhiṃ pattuṃ icchasi” Ja.i.24 (v. 167); “yadi dāyako dānaṃ deti… etaṃ bījaṃ hoti” Pv-a.8; or pot.; or with a participle, as: “yadi evaṃ sante” that being so, if this is so DN.i.61; “gahito yadi sīho te” if the lion is caught by you Mhvs.6, Mhvs.27
   ■ With other particles, e.g. yādi āsanamattaṃ pi even if only a seat Vv-a.39; yadi… atha kasmā if… how then Mil.4. yadi evaṃ… (tu) even if… yet (but) Pv-a.63 (y. e. pitā na rodati mātu nāma hadayaṃ mudukaṃ)
   ■ yadi va “or” (cp Vedic yadi vā “or be it that”) Dhp.195 (= yadi vā athavā Dhp-a.iii.252). So yadi vā at Ja.i.18 (v. 97: latā vā yadi vā rukkhā etc. Snp.119 (gāme vā yadi vâraññe)
2. as a strong particle of exhortation: yadi evaṃ if so, in that case, let it be that, alright, now then Pv-a.54 (y. e. yaṃ mayhaṃ desitaṃ ekassa bhikkhuno dehi), Pv-a.217 (y. e. yāvadatthaṃ gaṇhāhi: take as much as you like).

adv. formation, orig. loc., fr. ya˚; cp. Vedic yadi