frightening, alarming, shocking
Nightmares are frightening.
Insekten ohne Flügel sind nicht so erschreckend wie welche mit.
Insects without wings are not as frightening as those with them.
Tom ist erschreckend.
Tom is frightening.
That is frightening.
Erschreckend, dass mein Ex-Student für die Nazis arbeitete.
It's appalling that my former student worked for the Nazis.
— Oppenheimer (2023)
Gewitter sind gleichermaßen erschreckend wie aufregend.
Thunderstorms are both frightening and exciting.