hellish; fiendish; diabolical: an infernal plot.
extremely troublesome, annoying, etc.; outrageous: an infernal nuisance.
of, inhabiting, or befitting hell.
Classical Mythology. of or relating to the underworld.

Origin of infernal

1325–75; Middle English < Late Latin infernālis, equivalent to Latin infern(us) situated below, of the underworld (see inferior) + -ālis -al1
Related formsin·fer·nal·i·ty, nounin·fer·nal·ly, adverb

Synonyms for infernal Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for infernal

Contemporary Examples of infernal

Historical Examples of infernal

  • The lake by which the ancients entered the infernal regions.

  • And then—I might at a pinch describe the infernal regions, but not the other place.

    American Notes

    Rudyard Kipling

  • He is treated from that instant as a man who has done some infernal action.

    Little Dorrit

    Charles Dickens

  • It seemed to me that he was Pluto, the god of the infernal regions, and I was Proserpine.

    My Double Life

    Sarah Bernhardt

  • How long I stood for this infernal proceeding I do not know.

British Dictionary definitions for infernal



of or relating to an underworld of the dead
deserving hell or befitting its occupants; diabolic; fiendish
informal irritating; confounded
Derived Formsinfernality, nouninfernally, adverb

Word Origin for infernal

C14: from Late Latin infernālis, from infernus hell, from Latin (adj): lower, hellish; related to Latin inferus low
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for infernal

late 14c., in reference to the underworld, from Old French enfernal, infernal (12c.), from Late Latin infernalis "of the lower regions," from infernus "hell" (Ambrose), literally "the lower (world)," noun use of Latin infernus "lower, lying beneath," from infra "below" (see infra-). Meaning "devilish, hateful" is from early 15c. For the name of the place, or things which resemble it, the Italian form inferno has been used in English since 1834, from Dante. Related: Infernally.

Online Etymology Dictionary, © 2010 Douglas Harper