Synonyms and Antonyms of hellacious
- the hellacious heat was more than we could bear
- the pioneers survived a particularly hellacious river crossing with their covered wagon barely in one piece
arduous, Augean, backbreaking, challenging, demanding, difficult, effortful, exacting, formidable, grueling (or gruelling), hard, heavy, herculean, killer, laborious, moiling, murderous, pick-and-shovel, rigorous, rough, rugged, severe, stiff, strenuous, sweaty, tall, testing, toilsome, tough, uphill
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
cheap, easy, effortless, facile, light, mindless, simple, soft, undemanding