strenuous Definition

arduous, effortful, energetic, straining, vigorous, exhausting, tiring, hectic, tedious, rigorous, intense, intensive, laborious, gruelling, herculean, painstaking, tiresome, challenging, daunting, uphill, diligent, painful, difficult, heroic, onerous, exhaustive, hard, assiduous, tough, tireless, relentless, forceful, unremitting, heavy, fierce, ceaseless, insistent, cumbersome, harsh, stringent, indefatigable, active, resolute, persistent, debilitating, serious, incessant, burdensome, rigid, aggressive, tense, exacting, severe, stubborn, unstinting, extensive, untiring, robust, demanding, fervent, tenacious, sustained, formidable, violent, distressing, massive, intractable, dogged, considerable, hardship, unswerving, bitter, determined, substantial, steadfast, strong, immense, significant, great, entrenched, ingrained, tremendous, vivid, enormous, major, vibrant, dedicated, huge, vast, big, large, deep-rooted, labourious, wholesale,