Synonyms of appalling

1 Syllable
mean, gross, bad, lou, grim, dire
2 Syllables
heavy, grisly, sickie, horrid, grievous, scaring, vilest, dismaying, fearful, ghastlier, daunting, ugliest, uglier, frightful, viler, grody, dreadful, ghastly, woeful, awful, shocking, hideous, mondo, grabber, tragic, ugly, deathly, whaler
3 Syllables
direful, tremendous, alarming, gruesome, ghostlike, terrible, terrific, frightening, harrowing, astounding, terrifying, bad-looking, horrible, horrendous, petrifying, unnerving, revolting, unearthly, horrific
4 Syllables
unspeakable, disheartening, hard-featured, unbeautiful, formidable, defunctive, percussive
5 Syllables
discreditable, hyperphysical, undescribable, intimidating, unprepossessing, unutterable, inexpressible, indefinable
6 Syllables
incommunicable