əˈvərn ə l adjective
or aver·ni·an -nēən, -nyən
Usage: sometimes capitalized
Etymology: avernal from Latin Avernalis of Avernus, from Avernus, lake near Pozzuoli, Italy (now Lago Averno ), reputed because of its depth and stench to lead to the underworld, underworld + Latin -alis -al; avernian from Avern us + English -ian
: infernal