Oxford Dictionary English mix-up noun noun BrE BrE//ˈmɪks ʌp// ; NAmE NAmE//ˈmɪks ʌp// (informal) Add to my wordlistjump to other resultsa situation that is full of confusion, especially because somebody has made a mistake synonym muddle There has been a mix-up over the dates.See mix-up in the Oxford Advanced American DictionaryCheck pronunciation: mix-up oxfordlearnersdictionaries.com