backbreaking vs grueling

backbreaking and grueling both are adjectives.

Word	Noun	Adjective	Verb	Adverb
backbreaking	No	Yes	No	No
grueling	No	Yes	No	No

As adjectives, backbreaking and grueling are synonyms defined as:

backbreaking and grueling: characterized by effort to the point of exhaustion; especially physical effort

Other synonyms of backbreaking include arduous, gruelling, hard, heavy, laborious, operose, punishing, toilsome.

backbreaking (adjective)	grueling (adjective)
characterized by effort to the point of exhaustion; especially physical effort	characterized by effort to the point of exhaustion; especially physical effort