gruelling vs laborious

gruelling and laborious both are adjectives.

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

As adjectives, gruelling and laborious are synonyms defined as:

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

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

gruelling (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