nightmare

The story

1. Proto-Indo-European*nókʷts
2. Proto-Germanic*nahts
3. Proto-West Germanic*naht
4. Proto-Indo-European*mer-
5. Proto-Indo-European*mor-
6. Proto-Germanic*marǭ
7. Proto-West Germanic*marā
8. Proto-West Germanic*nahtmarā
9. Old English*nihtmare
10. Middle Englishnyghtmare
11. English todaynightmare

Inherited from Middle English nyghtmare. By surface analysis, night + mare. Cognate with Scots nichtmare and nichtmeer, Dutch nachtmerrie, Middle Low German nachtmār, German Nachtmahr.

First known use, by meaning

• from 19th c. A very unpleasant or frightening dream.
• from 20th c. Any bad, miserable, difficult or terrifying situation or experience that arouses anxiety, terror, agony or great displeasure.
• from 14th c. A demon or monster, thought to plague people while they slept and cause a feeling of suffocation and terror during sleep.
• from 16th c. A feeling of extreme anxiety or suffocation experienced during sleep; sleep paralysis.