- ghastly, grim, grisly, gruesome, macabre - shockingly repellent; inspiring horror; "ghastly wounds"; "the grim aftermath of the bombing"; "the grim task of burying the victims"; "a grisly murder"; "gruesome evidence of human sacrifice"; "macabre tales of war and plague in the Middle ages"; "macabre tortures conceived by madmen"
Antonym: unalarming (indirect, via alarming)