onerous
US /ˈɑː.nɚ.əs/
UK /ˈɑː.nɚ.əs/

1.
oneroso, gravoso, pesado
involving a great deal of effort, trouble, or difficulty
:
•
The new regulations impose onerous burdens on small businesses.
Las nuevas regulaciones imponen cargas onerosas a las pequeñas empresas.
•
He found the task to be quite onerous.
Encontró la tarea bastante onerosa.