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

Related Words for infernally

extremely, unbelievably, diabolically, horribly

Examples from the Web for infernally

Historical Examples of infernally

  • I feel sorry for her and that's all—deeply and infernally sorry.

    The Harbor

    Ernest Poole

  • He was so infernally certain that the Emperor would wipe the floor with us.

    The Island Mystery

    George A. Birmingham

  • This intuition, or whatever you may call it, is an infernally bad thing for you.

    The Seven Secrets

    William Le Queux

  • If you don't do this my position, as well as your own, will be infernally awkward.

    Lalage's Lovers

    George A. Birmingham

  • Her dissimulation, he was obliged to perceive, had been infernally deep.


    Henry James

British Dictionary definitions for infernally



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 infernally



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