nightmare
UK: /ˈnaɪt.meər/ | US: /ˈnaɪt.mer/
n. a frightening or unpleasant dream
n. a distressing experience or situation
n. (archaic) a demon or spirit believed to cause suffocating sensations during sleep
The word "nightmare" originates from Old English nihtmare, combining "night" (the time of darkness) and "mare" (an evil spirit or goblin in Germanic folklore believed to torment sleepers). The "mare" component derives from Proto-Germanic marōn, linked to oppressive or crushing sensations during sleep. Over time, the term shifted from describing a supernatural entity to the disturbing dreams it was thought to cause.
She woke up screaming from a terrifying nightmare.
The traffic jam was an absolute nightmare this morning.
In medieval tales, a nightmare was blamed for sleep paralysis.
His recurring nightmare always involved being chased.
The project turned into a bureaucratic nightmare.