maddening adjective
[more maddening; most maddening] : very annoying
▪ He has a maddening habit of interrupting other people. ▪ She shows a maddening inability to control her children.
▪ He has a maddening habit of interrupting other people. ▪ She shows a maddening inability to control her children.
— mad·den·ing·ly 
/ˈmædn̩ɪŋli/ adverb
▪ a maddeningly difficult problem ▪ maddeningly slow service
/ˈmædn̩ɪŋli/ adverb ▪ a maddeningly difficult problem ▪ maddeningly slow service
