Main entry: arduous
Definition: difficult to accomplish; demanding considerable mental effort and skill
Usage: the arduous work of preparing a dictionary
Main entry: heavy, grueling, gruelling, hard, laborious, backbreaking, arduous, toilsome, operose, punishing
Definition: characterized by effort to the point of exhaustion; especially physical effort
Usage: worked their arduous way up the mining valley; a grueling campaign; hard labor; heavy work; heavy going; spent many laborious hours on the project; set a punishing pace
Main entry: arduous, straining, strenuous
Definition: taxing to the utmost; testing powers of endurance
Usage: his final, straining burst of speed; a strenuous task; your willingness after these six arduous days to remain here- F.D.Roosevelt