'backbreaking' definitions:

Definition of 'backbreaking'

(from WordNet)
adjective
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: arduous, backbreaking, grueling, gruelling, hard, heavy, laborious, operose, punishing, toilsome]