Where does “nightmarishness” come from?

nightmarishness (English) comes from English nightmarish, from English nightmare, from English night, from Middle English nyght, from Middle English nighte, from Old English nyht, from Proto-West Germanic naht, from Proto-Germanic nahts — bare, naked.

nightmarishness (English): The state or condition of being nightmarish

Definitions

  1. The state or condition of being nightmarish

Ancestry of “nightmarishness”, step by step

nightmarishness traces back through two separate lines of ancestry.

via English nightmarish

StepLanguageWordMeaning
1EnglishnightmarishResembling a nightmare
2EnglishnightmareA demon or monster, thought to plague people...
3EnglishnightThe period between sunset and sunrise, when a...
4Middle EnglishnyghtAlternative form of nighte; Alternative form of...
5Middle Englishnightenight
6Old EnglishnyhtAlternative form of niht
7Proto-West Germanicnahtnight
8Proto-Germanicnahtsnight
9Proto-Indo-Europeannókʷtsnight
10Proto-Indo-Europeannegʷ-bare, naked

via English Ness

StepLanguageWordMeaning
1EnglishNessAn Ulster princess and the mother of Conchobar mac Nessa and Findchoem in the Ulster Cycle of Irish mythology. Daughter of Eochaid Sálbuide. Also the mother of Cormac Cond Longas by incest with Conchobar mac Nessa
2Middle Englishnesse
3Old Englishnæsnot, not at all; not; first/third-person singular...
4Proto-Germanicnasjąfoothill; headland; cape
5Proto-Indo-Europeannéh₂snose
Every word from Proto-Indo-European negʷ-Every word from Proto-Indo-European nókʷtsEvery word from Proto-Germanic nahts