atrocious, flagitious, grievous, monstrous -- (shockingly brutal or cruel; "murder is an atrocious crime"; "a grievous offense against morality"; "a grievous crime"; "no excess was too monstrous for them to commit")
atrocious, abominable, awful, dreadful, painful, terrible, unspeakable -- (exceptionally bad or displeasing; "atrocious taste"; "abominable workmanship"; "an awful voice"; "dreadful manners"; "a painful performance"; "terrible handwriting"; "an unspeakable odor came sweeping into the room")
atrocious, frightful, 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")