Synonyms and related words :
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