avataraṇa : [nt.] descending; entering; plunging into.

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

ava-taraṇa n. descending, alighting R. Śak
• 'rushing away, sudden disappearance', or for ava-tāraṇa, bhārâvat○ (cf. stanyâvataraṇa)
• translating L

Sanskrit-English Dictionary, by M. Monier William