adj. 25B6; adjective
a hideous smile : UGLY, repulsive, repellent, unsightly, revolting, gruesome, grotesque, monstrous, ghastly, reptilian; informal as ugly as sin.
hideous cases of torture : HORRIFIC, terrible, appalling, awful, dreadful, frightful, horrible, horrendous, horrifying, shocking, sickening, gruesome, ghastly, unspeakable, abhorrent, monstrous, heinous, abominable, foul, vile, odious, execrable.
beautiful, pleasant.