Synonyms and related words :
alarming, bloodcurdling, frightening, grim, grisly, gruesome, hair-raising, hideous, horrible, horrid, horrifying, macabre, paralyzing, petrifying, scary, shocking, stunning, stupefying, terrible, terror, terror-bearing, terror-breathing, terror-breeding, terror-bringing, terror-fraught, terror-giving, terror-inspiring, terror-striking, terrorful, terroristic