frightful

provoking horror; "an atrocious automobile accident"; "a frightful crime of decapitation"; "an alarming, even horrifying, picture"; "war is beyond all words horrible"- Winston Churchill; "an ugly wound"

extreme in degree or extent or amount or impact; "in a frightful hurry"; "spent a frightful amount of money"

extremely distressing; "fearful slum conditions"; "a frightful mistake"