nightmare

painajainen puhekieltä A female demon or monster, thought to plague people while they slept and cause a feeling of suffocation and terror during sleep.
1817, (w), Rob Roy:

It haunted me, however, more than once, like the nightmare.

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!

I had a nightmare that I tried to run but could neither move nor breathe.

With his crude potato-sack mask and fear-inducing toxins, The Scarecrow, a “psychopharmacologist” at an insane asylum, acts as a conjurer of nightmares, capable of turning his patients’ most terrifying anxieties against them.

Cleaning up after identity theft can be a nightmare of phone calls and letters.