adj. 25B6; adjective
a Herculean task : ARDUOUS, gruelling, laborious, back-breaking, onerous, strenuous, difficult, formidable, hard, tough, huge, massive, uphill; demanding, exhausting, taxing; archaic toilsome.
his Herculean build : STRONG, muscular, muscly, powerful, robust, solid, strapping, brawny, burly; informal hunky, beefy, hulking.
easy, puny.