āsīvisa : [m.] a snake; whose poison is in the fangs.

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

Āsīvisa Derivation uncertain. The BSk. āsīviṣa (e. g. Jtm 3161) is a Sanskritisation of the Pali. To suppose this to come from ahi + visa (snake's poison) would give a wrong meaning, and leave unexplained the change from ahi to āsi] a snake Vin iv.108; S iv.172; A ii.110; iii. 69; J i.245; ii.274; iv.30, 496; v.82, 267; Pug 48; Vism 470 (in comp.); DhA i.139; ii.8, 38; SnA 334, 458, 465; VvA 308.

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