undescribable

abominable alarming appalling atrocious awful beastly beyond words calamitous defying description description detestable dire disgusting dreadful evil execrable fearful frightening frightful heinous horrible horrid incommunicable inconceivable indefinable indescribable ineffable inexpressible inhuman loathsome monstrous nameless obnoxious odious offensive outrageous overwhelming preternatural repellent repugnant repulsive revolting shocking unbelievable unimaginable unutterable