/ Dictionary / Index N nightmarish: Meaning and Definition of Find definitions for: night•mar•ish Pronunciation: (nīt'mâr"ish), [key] — adj. resembling a nightmare, esp. in being terrifying, exasperating, or the like: his nightmarish experience in a concentration camp. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: nightmarish (Thesaurus) nightmare night monkey Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language