onerous
— Tillægsord
– Engelsk
~ not easily borne; wearing; "the burdensome task of preparing the income tax return"; "my duties weren't onerous; I only had to greet the guests"; "a taxing schedule"
onerously
— Biord
– Engelsk
~ in an onerous manner
onerousness
— Navneord
– Engelsk
~ unwelcome burdensome difficulty