Found 2 items, similar to nightmarish.
English → English (WordNet) Definition: nightmarish nightmarish adj : extremely alarming [syn: bloodcurdling, hair-raising]
English → English (gcide) Definition: nightmarish nightmarish \nightmarish\ adj. Terrifying, as if in a nightmare[2]; resembling a nightmare[2]. Syn: bloodcurdling, hair-raising. [WordNet 1.5]