ˌædəˈlɛsənt dʒəˈdʒuːn ˈdʒuːvənaɪl ˈdʒuːvənaɪl ˈpjʊə.ɹaɪl ˈpjʊɹɪl displaying or suggesting a lack of maturity adolescent insecurity jejune responses to our problems their behavior was juvenile puerile jokes