Adjective: horror-struck hor-ur strúk or hór-ur strúk [N. Amer], hó-rur strúk [Brit]- Stricken with horror
"I was horror-struck at the thought of being late for my interview";
- horrified, horror-stricken
See also: afeard [archaic], afeared [archaic], afraid, 'fraid [non-standard]