horrifying (adj.)
- appalling
- astounding
- atrocious
- awe-inspiring
- awesome
- awful
- baneful
- beastly
- dire
- direful
- dread
- dreaded
- dreadful
- fell
- formidable
- ghastly
- ghoulish
- grim
- grisly
- gruesome
- hideous
- horrendous
- horrible
- horrid
- horrific
- lurid
- macabre
- morbid
- redoubtable
- rotten
- shocking
- terrible
- terrific
- terrifying
- tragic
- tremendous
- unspeakable