Synonyms of nightmarish in English:

nightmarish


See definition of nightmarish

adjective

1‘Grant fired at the nightmarish, clawing figure before him’

SYNONYMS
unearthly, monstrous, ghostly, spine-chilling, horrific, macabre, hideous, unspeakable, gruesome, grisly, ghastly, harrowing, hair-raising, disturbing, Kafkaesque
informal scary, creepy
rare phantasmagorical