\In*fer"nal\, a. [F. infernal, L. infernalis, fr.
infernus that which lies beneath, the lower. See {Inferior}.]
1. 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.
         The Elysian fields, the infernal monarchy. --Garth.
2. 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.
         The instruments or abettors in such infernal
         dealings.                             --Addison.
{Infernal machine}, a machine or apparatus maliciously
   designed to explode, and destroy life or property.
{Infernal stone} (lapis infernalis), lunar caustic; formerly
   so called. The name was also applied to caustic potash.
Syn: Tartarean; Stygian; hellish; devilish; diabolical;
     satanic; fiendish; malicious.

\In*fer"nal\, n.
An inhabitant of the infernal regions; also, the place
itself. [Obs.] --Drayton.