A joint that can rotate within a socket WordNet 3.0 & Open English WordNet

The ball-and-socket joint is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. Wikipedia

allows rotational movement but prevents transtional movement to the member attached to it Wikidata

A joint in which one segment has a rounded end and the next segment has a bowl-shaped end, with the rounded end being fitted into the bowl shape, allowing the first segment to move around an indefinite number of axes which have one common center. Wiktionary

Type of joint. Wiktionary (translation)