definition of
gruelling

[1] #1 gruelling s. [arduous, backbreaking, grueling, hard, heavy, laborious, operose, punishing, toilsome] 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 punishin. wn