Oxford Dictionary English in-joke noun noun BrE BrE//ˈɪn dʒəʊk// ; NAmE NAmE//ˈɪn dʒoʊk// Add to my wordlistjump to other resultsa joke that is only understood by a particular group of peopleSee in-joke in the Oxford Advanced American DictionaryCheck pronunciation: in-joke oxfordlearnersdictionaries.com