Word Study
nightmarish
WORDNET DICTIONARY
Adjective nightmarish has 1 sense
- nightmarish(s = adj.all) bloodcurdling, hair-raising - extremely alarming; Array
CIDE DICTIONARY
nightmarish, adj.
Terrifying, as if in a nightmare{2}; resembling a nightmare{2}. [WordNet 1.5]
For further exploring for "nightmarish" in Webster Dictionary Online