āpatti : [f.] getting into; an ecclesiastical offence.

A.P. Buddhadatta Mahathera, Concise Pali-English and English-Pali Dictionary [available as digital version from Metta Net, Sri Lanka]

Āpatti (f.) [Sk. āpatti, fr. ā + pad, cp. apajjati & BSk. āpatti, e. g, Divy 330] an ecclesiastical offence (cp. Kvu trsl. 362 n. 1), Vin i.103 (˚khandha), 164 (˚ŋ paṭikaroti), 322 (˚ŋ passati), 354 (avasesā & anavasesā); ii.2 sq. (˚ŋ ropeti), 59, 60 (˚pariyanta), 88 (˚adhikaraṇa), 259 (˚ŋ paṭikaroti); iv.344; D iii.212 (˚kusalatā); A i.84 (id.), 87; ii.240 (˚bhaya); Dhs 1330 sq. (cp. Dhs trsl. 346). <-> anāpatti Vin iii.35.
  ˚vuṭṭhānatā forgiveness of an offence Vin ii.250 (put before anāpatti).

Pali-English Dictionary, TW Rhys Davids, William Stede,

ltung ba

[translation-san] {LCh,C,MSA} āpatti

[translation-san] {LCH} patita

[translation-san] {C} patati (=anuprāpnoti = upapadyate)

[translation-san] {C} patana

[translation-san] {MSA} pata

[translation-san] {C} prapātitva

[translation-eng] {Hopkins} verb: to fall, sin; commit an infraction noun: fall; infraction; sin

[translation-eng] {C} falling apart; fall down; fall on; fall into; fall from; drops; offense

Jeffrey Hopkins' Tibetan-Sanskrit-English Dictionary