The Oxford Thesaurus An A-Z Dictionary of Synonyms - hideous adj.

1) grotesque, ugly, repulsive, revolting, repellent, monstrous, beastly, gorgonian, unsightly, ghastly, disgusting, grisly, nauseating, nauseous, sickening, gruesome: Suddenly, a hideous face appeared at the kitchen window. 2) foul, abhorrent, heinous, horrifying, appalling, outrageous, abominable, vile, shocking, loathsome, contemptible, hateful, odious, atrocious, horrific, beastly, damnable, execrable: Two hideous crimes were committed here last night.