Synonyms and related words :
abhorrent, abominable, alarming, appalling, atrocious, awful, awing, chilling, daunting, deadly, deterrent, deterring, disagreeable, disconcerting, discouraging, disheartening, dismaying, disquieting, dreadful, fear-inspiring, fearful, fearsome, forbidding, formidable, foul, frightening, ghastly, grisly, gruesome, hideous, horrendous, horrible, horrid, horrific, horrifying, howling, loathsome, lurid, macabre, nasty, nauseating, nauseous, offensive, overawing, repelling, repugnant, repulsive, revolting, rousing, scaring, scary, shocking, startling, terrible, terrific, thumping, ugly, unspeakable, vile, whacking