ar·du·ous 
/ˈɑɚʤəwəs/ adjective
/ˈɑɚʤəwəs/ adjective [more arduous; most arduous] : very difficult
▪ He went through a long and arduous training program. ▪ arduous efforts ▪ years of arduous study ▪ an arduous chore/duty/job/task ▪ an arduous journey across miles of desert
▪ He went through a long and arduous training program. ▪ arduous efforts ▪ years of arduous study ▪ an arduous chore/duty/job/task ▪ an arduous journey across miles of desert
— ar·du·ous·ly adverb
▪ working arduously
▪ working arduously
— ar·du·ous·ness noun [noncount]
