Avernalis

Ăvernālis, e, adj. [Avernus],

of or pertaining to Lake Avernus : aquae, Hor. Epod. 5, 26: Nymphae, Ov. M. 5, 540: Naiades, Stat. S. 2, 6, 101: Sibylla, i. e. dwelling by the lake , Prop. 5, 1, 49.