Grievous
Part of speech: adjective
Definition: Causing grief, pain or sorrow serious, grave, dire or dangerous
Atrocious
Part of speech: adjective
Definition: frightful, evil, cruel or monstrousoffensive or heinousvery bad; abominable or disgusting
Example sentence: Whereas religious prayers sing of peace and harmony, religion has divided human beings through an atrocious history of enmity and bloodshed. Yet, behind the veil of superficiality and hypocrisy, I always believed in the inherent beauty of God that lies at the essence of all true spiritual paths.