(a.) Burdensome; oppressive\.

Herculean annoying arduous arduously backbreaking besetting bothersome burdensome burdensomely crushing cumbersome cumbrous demanding difficult difficultly effortful encumbering exacting exhausting exigent forced grievous grinding grueling hampering hard hard-earned hard-fought hardly harsh heavy heavy-handed hefty impedimental impeding impeditive incumbent irksome killing labored laborious laboriously lumpish massive onerously operose oppressive overburdensome painful plaguey ponderous punishing strained strenuous superincumbent taxing toilsome toilsomely tough troublesome trying tyrannous unruly unwieldy uphill vexatious wearing wearisome wearying weighty