definition of
frightful

[1] #1 frightful s. [atrocious, horrifying, horrible, ugly] 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". wn

[2] #2 frightful s. [fearful] extremely distressing; "fearful slum conditions"; "a frightful mistake". wn