ghast·ly 
(găstlē)
(găstlē)adj. ghast·li·er, ghast·li·est
1. Causing shock, revulsion, or horror; terrifying: a ghastly murder.
2. Resembling a ghost; pale or pallid.
3. Extremely unpleasant or bad: "in the most abominable passage of his ghastly little book" (Conor Cruise O'Brien).
[Alteration (influenced by GHOST) of Middle English gastli, from gasten, to terrify; see AGHAST.]
ghastli·ness n.
ghastly adv.
Synonyms: ghastly, gruesome, grisly, grim, macabre
These adjectives describe what is shockingly repellent in aspect or appearance. Ghastly suggests the shock or horror inspired by violent death or bodily harm: the ghastly toll of trench warfare; a ghastly disfiguring disease. Gruesome and grisly often describe what horrifies or revolts because of its graphic nature: a gruesome murder scene; read about the grisly details of the accident. Grim refers to what repels because of its harsh or unnerving nature: the grim task of burying the earthquake victims. Macabre can suggest the fascination as well as the horror of unnatural death and is often used of artistic works: a murder mystery with a macabre twist at the end.
These adjectives describe what is shockingly repellent in aspect or appearance. Ghastly suggests the shock or horror inspired by violent death or bodily harm: the ghastly toll of trench warfare; a ghastly disfiguring disease. Gruesome and grisly often describe what horrifies or revolts because of its graphic nature: a gruesome murder scene; read about the grisly details of the accident. Grim refers to what repels because of its harsh or unnerving nature: the grim task of burying the earthquake victims. Macabre can suggest the fascination as well as the horror of unnatural death and is often used of artistic works: a murder mystery with a macabre twist at the end.