ball-and-socket joint
noun [ C ] anatomy specialized uk/ˌbɔːl.ənˈsɒk.ɪt dʒɔɪnt/ us/ˌbɑːl.ənˈsɑː.kɪt dʒɔɪnt/
球窝连接;球窝关节
a joint (= a place where two bones are connected) consisting of a round end and a hollow socket that fit together and move easily
The hip joint is a ball-and-socket joint. 髋关节属于球窝关节。