undisciplined /ˌʌnˈdɪsəplənd/ adjective /ˌʌnˈdɪsəplənd/
adjective
Learner's definition of UNDISCIPLINED
[more undisciplined; most undisciplined]
: behaving in a way that is not properly controlled, organized, serious, etc. : lacking discipline缺乏管教的;不遵守纪律的;没规矩的