exhausting, demanding, tiring, severe, taxing, punishing, strenuous, arduous
she worked a gruelling 18 hours shift at the restaurant.
The man was in gruelling pain after he was attacked by the great white shark.
The spelling gruelling is a variant, but the US spelling of the adjective is grueling (demanding, arduous).
Very tiring or exhaustgrueling means tierd or tiring
To cope with her gruelling schedule she must maintain a very high level of fitness.
arduous, backbreaking, grueling, gruelling, hard, heavy, laborious, operose, punishing, toilsome
"Gruelling" refers to something that is extremely tiring, demanding, or exhausting, often involving intense effort or hardship. It can describe physical challenges, such as a strenuous workout or a long journey, as well as mental tasks that require significant concentration and perseverance. The term conveys a sense of being worn out or overwhelmed by the demands placed on a person.
They are synonyms.
Synonyms
Relative and kin are synonyms.
The word is spelt gruelling in British English and grueling in American English.
They are synonyms.