gruelling | meaning of gruelling in Longman Dictionary of Contemporary English | LDOCE

From Longman Dictionary of Contemporary Englishgruellinggru‧el‧ling British English, grueling American English /ˈɡruːəlɪŋ/ adjective    DIFFICULTvery difficult and tiring  The cast took a break from their gruelling schedule.  a grueling journey► see thesaurus at tiringExamples from the Corpusgruelling• The Le Mans 24 hour race is the most gruelling event in the motor-racing calendar.• Events include Hang Tough - a gruelling game of aerial chess - and Atlaspheres, a battle fought in giant globes.• It could take fourteen weeks to complete the gruelling journey on foot from London to Rome in the Middle Ages.• A chance for a last flourish and a bit of fun at the end of a gruelling league campaign.• McAllister should be on his knees after a gruelling month at Elland Road.• Middlesbrough face a gruelling ten-match programme in April.• He has a serious nature and his powers of concentration are a boon when it comes to his gruelling training schedule.• In his gruelling work schedule, sixty-year old Garrett continues at a rate that would tax many men half his age.