arduous
1. [ adjective ] characterized by toilsome effort to the point of exhaustion; especially physical effort
Synonyms: hard grueling punishing heavy laborious labourious gruelling toilsome backbreaking
Examples:

"worked their arduous way up the mining valley" "a grueling campaign" "hard labor" "heavy work" "heavy going" "spent many laborious hours on the project"

Related terms: effortful
2. [ adjective ] taxing to the utmost; testing powers of endurance
Synonyms: straining strenuous
Examples:

"his final, straining burst of speed" "a strenuous task" "your willingness after these six arduous days to remain here"- F.D.Roosevelt

Related terms: effortful
3. [ adjective ] difficult to accomplish; demanding considerable mental effort and skill
Examples:

"the arduous work of preparing a dictionary"

Related terms: difficult
Similar spelling:   arduously
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