diabolic - awful
‘Diabolic’ is associated with the word ‘devil’ and therefore is used to describe somebody or something particularly evil or cruel. However, in British English, it's more commonly used to express something disgracefully or shockingly bad.
The police officer found three dead bodies in the room. It was a diabolic scene.
Our working conditions are absolutely diabolical! The factory simply isn’t safe.
Her actions were all undertaken as part of a cunning and diabolic plot.