compos mentis
adjective [ after verb ] humorous uk/ˌkɒm.pɒs ˈmen.tɪs/ us/ˌkɑːm.pəs ˈmen.t̬əs/
心智健全的;神志清楚的;头脑健康的
able to think clearly and be in control of and responsible for your actions
She was very old but still compos mentis. 那时她很老了，可是依然头脑清晰。