in loco parentis
adjective [ after verb ], adverb formal uk/ɪn ˌləʊ.kəʊ pəˈren.tɪs/ us/ɪn ˌloʊ.koʊ pəˈren.t̬ɪs/
（对别人的孩子）代尽父母的责任
being responsible for a child while the child's parents are absent
While children are in school, teachers are legally in loco parentis. 孩子在校期间老师就是法定监护人。