petrified, scared stiff, frightened/scared out of one's wits, scared witless, frightened/scared to death, terror-stricken, terror-struck, horror-stricken, horror-struck, paralysed with fear, horrified, panic-stricken, with one's heart in one's mouth, shaking in one's shoes, shaking like a leaf, frantic, hysterical, beside oneself;

scared, frightened, afraid;

Scottish feart

informal in a cold sweat, in a (blue) funk

British informal funky, windy

North American informal spooked

vulgar slang scared shitless, shit scared, shitting bricks, bricking oneself

dialect frit

archaic afeared, affrighted

petrify, scare stiff, scare/frighten someone out of their wits, scare witless, scare/frighten to death, scare/frighten the living daylights out of, scare/frighten the life out of, scare the hell out of, strike terror into, fill with fear, put the fear of God into, make someone's blood run cold, chill someone's blood, paralyse with fear, make someone's flesh creep, give someone goose pimples, make someone's hair stand on end, send into a cold sweat, make someone shake in their shoes;

horrify, alarm, appal, panic, throw into a panic;

frighten, scare

informal scare the pants off, make someone's hair curl, scarify

British informal throw into a blue funk

Irish informal scare the bejesus out of

North American informal spook

vulgar slang scare shitless, scare the shit out of

archaic affright