nightmare

Pluralnightmares

1. 1
   bad dreamnouncountable

   A frightening or very unpleasant dream that occurs during sleep.

   He still remembers a vivid nightmare he had as a teenager.

   After the accident she suffered recurring nightmares for months.

   UsageYou have a nightmare, often about something: she had a nightmare about falling.

   Note

   Behind the everyday word stands an old belief. Old English *nihtmare joins night to mare, an evil spirit thought to afflict a sleeper, so the bad dream took its name from the spirit blamed for it. Despite the spelling, no horse is involved. Source

   Checked 2 Nov 2026 · 4 facts

   • The reconstructed Old English *nihtmare combines night and mare. en.wiktionary.org
   • Mare denotes an evil spirit believed to torment sleepers. en.wiktionary.org
   • The name nightmare derives from the spirit believed to cause frightening dreams. en.wikipedia.org
   • The mare element is etymologically unrelated to the word for a female horse. en.wikipedia.org
2. 2
   awful situationnounfigurativelycountable

   Any situation or experience so unpleasant, difficult, or frightening that it causes deep anxiety, terror, anguish, or displeasure.

   The morning commute turned into a nightmare after three trains were canceled.

   Coordinating the schedules of forty volunteers became a logistical nightmare.

   UsageTwo patterns: a nightmare of something, and an adjective before it: a logistical nightmare, a complete nightmare.

   Similarordeal, disaster, horror, hell, torment

   Oppositedream, delight, joy

   Note

   C. Hamilton Ellis used it in 1941 to call the façade of St. Pancras a nightmare of improbable Gothic. Source

   Checked 2 Nov 2026 · 1 fact

   • C. Hamilton Ellis described the façade of St. Pancras as a nightmare of improbable Gothic in 1941. en.wiktionary.org
3. 3
   nounarchaic

   A demon or monster believed to plague people during sleep, causing a sensation of suffocation and terror.

   It haunted me, however, more than once, like a night-mare.

   1817, [Walter Scott], Rob Roy

   I started, hourly, from dreams of unutterable fear, to find the hot breath of the thing upon my face, and its vast weight—an incarnate Night-Mare that I had no power to shake off—incumbent eternally upon my heart!

   1843, Edgar Allan Poe, The Black Cat

   Note

   Here the word names the creature itself, and the use is archaic, at home now in folklore and retellings of it. Older writers often hyphenated and capitalized it. Walter Scott's Rob Roy (1817) has something haunt the narrator "like a night-mare," and Poe's The Black Cat (1843) imagines "an incarnate Night-Mare" weighing on the heart. Source

   Checked 2 Nov 2026 · 5 facts

   • Historical writers used hyphenated and capitalized forms. eapoe.org
   • Walter Scott wrote Rob Roy, first published in 1817. en.wikipedia.org
   • Rob Roy's narrator uses the words "like a night-mare". en.wiktionary.org
   • Edgar Allan Poe wrote The Black Cat, first published in 1843. en.wikipedia.org
   • The Black Cat describes "an incarnate Night-Mare" weighing upon the narrator's heart. eapoe.org

Showing meanings only. Show all 7