"stop that god-awful racket"
extremely evil or cruel; expressive of cruelty or befitting hell;
"something demonic in him--something that could be cruel"
"fires lit up a diabolic scene"
"diabolical sorcerers under the influence of devils"
"a fiendish despot"
"infernal instruments of war"
- This child has had a hellish life.
- The weather has been hellish recently.
- We've had a hellish time lately.