nightmarish

[ nahyt-mair-ish ]

/ ˈnaɪtˌmɛər ɪʃ /

resembling a nightmare, especially in being terrifying, exasperating, or the like: his nightmarish experience in a concentration camp.

Origin of nightmarish

First recorded in 1825–35; nightmare + -ish¹

night·mar·ish·ly, adverb night·mar·ish·ness, noun

Obama officials have to do a far better job of helping all Syrians see that this nightmarish future could surpass the Assad past.

Face the Assad Reality In Syria |Frank G. Wisner, Leslie H. Gelb |January 26, 2014 |DAILY BEAST
Rather than use metaphors that point toward nightmare, we would do better to turn our gaze to nightmarish reality itself.

The Army Life, Mundane and Hideously Violent, by Turns |Brian Van Reet |August 29, 2013 |DAILY BEAST
Most Republican senators don't share this nightmarish vision of their country, thank goodness.

Why You Shouldn't #StandWithRand |David Frum |March 7, 2013 |DAILY BEAST
But they do answer to an activist base that shares a nightmarish vision of President Obama.

Why You Shouldn't #StandWithRand |David Frum |March 7, 2013 |DAILY BEAST

Maybe something of the violence and nightmarish quality of the early short stories had to do with that.

All Novels Are Spy Novels: Ian McEwan Talks ‘Sweet Tooth’ and His Life |Maya Jaggi |November 15, 2012 |DAILY BEAST
This novel is an emotional statement of those "nightmarish" days.

The Created Legend |Feodor Sologub
Against the glow of the green light inside the cavern he saw a nightmarish monster rising to its feet.

Loot of the Void |Edwin K. Sloat
Bart's wrist, after a few days of nightmarish pain when he tried to pick up anything heavy, had healed.

The Colors of Space |Marion Zimmer Bradley
It was bad enough, Cruthers thought, that these ants were six feet tall, but it was nightmarish to see them in three colors.

Martian V.F.W. |G.L. Vandenburg
The words one knows so well have a nightmarish meaning in this country.

Nostromo: A Tale of the Seaboard |Joseph Conrad