gruelling
adjective
[ ˈɡrʊəlɪŋ ]
• extremely tiring and demanding.
• "a gruelling schedule"
Similar:
exhausting,
tiring,
fatiguing,
wearying,
enervating,
taxing,
draining,
sapping,
debilitating,
demanding,
exacting,
trying,
difficult,
hard,
arduous,
laborious,
back-breaking,
strenuous,
harsh,
severe,
stiff,
punishing,
crushing,
crippling,
grinding,
brutal,
relentless,
unsparing,
killing,
murderous,
hellish,
knackering,
exigent,
Origin:
mid 19th century: from the verb gruel ‘exhaust, punish’, from an old phrase get one's gruel ‘receive one's punishment’.