onerous
US /ˈɑː.nɚ.əs/
UK /ˈɑː.nɚ.əs/

1.
gravoso, oneroso, difficile
involving a great deal of effort, trouble, or difficulty
:
•
The new regulations impose onerous burdens on small businesses.
Le nuove normative impongono oneri gravosi alle piccole imprese.
•
He found the task to be quite onerous.
Ha trovato il compito piuttosto gravoso.