backbreaking

Adj.

1.

backbreaking - characterized by toilsome 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" Synonyms: arduous, grueling, gruelling, laborious, toilsome, punishing, hard, heavy

arduous, effortful, grueling, gruelling, hard, heavy, laborious, punishing, toilsome