of or pertaining to or suitable for the lower regions, inhabited, according to the ancients, by the dead; pertaining to pluto's realm of the dead, the tartarus of the ancients.-of or pertaining to, resembling, or inhabiting, hell; suitable for hell, or to the character of the inhabitants of hell; hellish; diabolical; as, infernal spirits, or conduct.-an inhabitant of the infernal regions; also, the place itself.