backbreaking vs laborious

backbreaking and laborious both are adjectives.

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

As adjectives, backbreaking and laborious are synonyms defined as:

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

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

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