adjective
infernal
in-FUR-nul/ɪnˈfɜːrnl/
Extremely annoying or troublesome.
The infernal alarm makes the tired man cover his ears.

Etymology
Lower regions became Hell, and “hellish” extended to what feels intensely annoying.
More examples
- She finally silences the infernal buzzing.
- The infernal machine jams again.
Forms
infernal
Similar words
- annoying
- A more neutral and weaker expression of irritation.
- maddening
- Emphasizes intense frustration.