(a.) Grievous to be borne; causing uneasiness or fatigue; oppressive.

Herculean annoying arduous backbreaking besetting bothersome crushing cumbersome cumbrous demanding distressing effortful encumbering exacting exhausting exigent forced grievous grinding grueling hampering hard-earned hard-fought harsh heavy hefty impedimental impeding impeditive incumbent irksome killing labored laborious lumpish massive onerous operose oppressive overburdensome painful plaguey punishing strained strenuous superincumbent taxing toilsome tough troublesome trying tyrannous unwieldy uphill vexatious wearing wearisome wearying weighty worrisome worrying