characterized by effort to the point of exhaustion; especially physical effort; 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

[ Syn: backbreaking , grueling , gruelling , hard , heavy , laborious , operose , punishing , toilsome ]

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: straining , strenuous ]

difficult to accomplish; demanding considerable mental effort and skill; the arduous work of preparing a dictionary'