grueling

[ groo-uh-ling, groo-ling ]
/ ˈgru ə lɪŋ, ˈgru lɪŋ /

adjective

exhausting; very tiring; arduously severe: the grueling Boston marathon.

noun

any trying or exhausting procedure or experience.
Also especially British, gru·el·ling.

Origin of grueling

1850–55; slang gruel punishment (noun), punish (v.) + -ing2, -ing1

OTHER WORDS FROM grueling

gru·el·ing·ly, adverb

Words nearby grueling