grueling
UK: ˈɡruːəlɪŋ | US: ˈɡruəlɪŋ
adj. extremely tiring or demanding, often to the point of exhaustion
The word "grueling" derives from "gruel," a simple, bland food historically associated with poverty or punishment (e.g., prisoners or laborers subsisting on gruel). The suffix "-ing" transforms it into an adjective, metaphorically describing an experience as harsh or exhausting as enduring gruel. The term gained its modern sense in the 19th century, emphasizing extreme physical or mental strain.
The marathon was a grueling test of endurance.
She completed the grueling 12-hour shift without breaks.
Training for the Olympics involves grueling daily workouts.
The expedition through the desert was grueling but rewarding.
He described the exam as the most grueling challenge of his academic career.