[ nahyt-mair ]
/ ˈnaɪtˌmɛər /

WATCH NOW: The Suffocating History Behind The Word "Nightmare"

WATCH NOW: The Suffocating History Behind The Word "Nightmare"

It's dark. You're alone. Was that a footstep? Did something just brush up against you? You fight to get up, but you're stuck ... right on top of you is a horrifying nightmare. Sorry, did you say a nightmare was on top of me?



a terrifying dream in which the dreamer experiences feelings of helplessness, extreme anxiety, sorrow, etc.
a condition, thought, or experience suggestive of a nightmare: the nightmare of his years in prison.
(formerly) a monster or evil spirit believed to oppress persons during sleep.

Origin of nightmare

Middle English word dating back to 1250–1300; see origin at night, mare2

synonym study for nightmare

1. See dream. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Examples from the Web for nightmare

British Dictionary definitions for nightmare

/ (ˈnaɪtˌmɛə) /


a terrifying or deeply distressing dream
  1. an event or condition resembling a terrifying dreamthe nightmare of shipwreck
  2. (as modifier)a nightmare drive
a thing that is feared
(formerly) an evil spirit supposed to harass or suffocate sleeping people

Derived forms of nightmare

nightmarish, adjectivenightmarishly, adverbnightmarishness, noun

Word Origin for nightmare

C13 (meaning: incubus; C16: bad dream): from night + Old English mare, mære evil spirit, from Germanic; compare Old Norse mara incubus, Polish zmora, French cauchemar nightmare
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

Medical definitions for nightmare

[ nītmâr′ ]


A dream arousing feelings of intense fear, horror, and distress.
An event or experience that is intensely distressing.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.