1 characterized by or performed with much energy or force; "strenuous exercise"
2 taxing to the utmost; testing powers of endurance; "his final, straining burst of speed"; "a strenuous task"; "your willingness after these six arduous days to remain here"- F.D.Roosevelt [syn: arduous, straining]
- Portuguese: urgente
requiring great exertion
- Portuguese: exigente
Herculean, active, arduous, breathless, burdensome, demanding, determined, difficult, dogged, dynamic, eager, earnest, effortful, energetic, enthusiastic, exhausting, hard, indefatigable, intense, laborious, lusty, mean, operose, persistent, pertinacious, red-blooded, resolute, sincere, taxing, tenacious, tireless, tiring, toilsome, tough, uphill, vigorous, vital, wicked, zealous