herculean

1 requiring considerable physical or mental effort the herculean task of grading 60 student essays over one weekend Synonyms arduous, Augean, backbreaking, challenging, demanding, difficult, effortful, exacting, formidable, grueling (or gruelling), heavy, hellacious, hard, killer, laborious, moiling, murderous, pick-and-shovel, rigorous, rough, rugged, severe, stiff, strenuous, sweaty, tall, testing, toilsome, tough, uphillRelated Words abstract, abstruse, complex, complicated, elusive, hairy, insoluble, intricate, involved, knotty, opaque, problematic (also problematical), recondite, serious, spiny, stubborn, thorny, ticklish, tricky; bruising, burdensome, exhausting, labored, onerous, oppressive, stressful, taxing, tight, trying; annoying, bothersome, distressing, irksome, troublesome, vexatious; grievous, grim, strict, stringent; brutal, cruel, inhuman, painfulNear Antonyms achievable, clear, doable, elementary, manageable, uncomplicated; comforting, gentle, painless, relaxed, smooth, soothing; accessible, friendly, idiotproof, user-friendlyAntonyms cheap, easy, effortless, facile, light, mindless, simple, soft, undemanding

2 unusually large a herculean banquet table that took eight men to lift it Synonyms astronomical (also astronomic), Brobdingnagian, bumper, colossal, cosmic (also cosmical), cyclopean, elephantine, enormous, galactic, gargantuan, giant, gigantesque, gigantic, grand, huge, heroic (also heroical), Himalayan, humongous (also humungous), immense, jumbo, king-size (or king-sized), leviathan, mammoth, massive, mega, mighty, monster, monstrous, monumental, mountainous, oceanic, pharaonic, planetary, prodigious, super, super-duper, supersize, supersized, titanic, tremendous, vast, vasty, walloping, whacking, whoppingRelated Words big, bulky, considerable, extensive, good, goodly, great, gross, handsome, hefty, hulking, largish, major, outsize (also outsized), overgrown, oversize (or oversized), sizable (or sizeable), substantial, tidy, voluminous; august, formidable, grandiose, imposing, lofty, majestic; cavernous, monolithic, overwhelming, staggering, stupendous, towering; boundless, immeasurable, infiniteNear Antonyms little, mini, petite, pint-size (or pint-sized), puny, small, smallish, undersized (also undersize); dinky, dwarfish, half-pintAntonyms bantam, bitty, diminutive, infinitesimal, Lilliputian, little bitty, micro, microminiature, microscopic (also microscopical), midget, miniature, minuscule, minute, pocket, pygmy, teensy, teensy-weensy, teeny, teeny-weeny, tiny, wee