skeleton service
noun [ S ] UK uk/ˈskel.ɪ.tən ˌsɜː.vɪs/ us/ˈskel.ɪ.t̬ən ˌsɝː.vɪs/
C1 （公交系统等在特定时间提供的）最基本的有限服务
the operation of something such as a transport system in an extremely limited way at certain times
The local bus company only runs a skeleton service on Sundays. 当地公交公司在星期天仅运营最基本的线路。