ball-and-socket joint

[ bawl-uhn-sok-it joint ]

noun

1. Also called enarthrosis. Anatomy, Zoology. a joint in which the rounded end of one bone fits into a cuplike end of the other bone, allowing for relatively free rotary motion, as at the hip or shoulder.
2. Also called ball joint. a similar joint between rods, links, pipes, etc., consisting of a ball-like termination on one part held within a concave, spherical socket on the other.

ball-and-socket joint

noun

1. a coupling between two rods, tubes, etc, that consists of a spherical part fitting into a spherical socket, allowing free movement within a specific conical volume
2. Also calledmultiaxial joint anatomy a bony joint, such as the hip joint, in which a rounded head fits into a rounded cavity, allowing a wide range of movement

ball-and-socket joint

/ bôl′ən-sŏk′ĭt /

1. A joint, such as the shoulder or hip joint, in which a spherical knob or knoblike part of one bone fits into a cavity or socket of another, so that some degree of rotary motion is possible in every direction.
2. A mechanical device consisting of a spherical knob at the end of a shaft that fits securely into a socket. Ball-and-socket joints are used to connect parts of a machine that require rotary movement in nearly all directions. Ball-and-socket joints allow the front wheels of a car to be turned by the steering mechanism.

Word History and Origins

Origin of ball-and-socket joint¹

First recorded in 1660–70

Example Sentences

In this case she adopted a ball-and-socket joint—the kind by which older astronomers mounted their telescopes.

From Project Gutenberg

The head is joined to the atlas by a beautiful ball-and-socket joint.

From Project Gutenberg

It is a bath that can be rocked, or inclined in any direction, for its center rests upon a ball-and-socket joint.

From Project Gutenberg

Igimang, ball-and-socket joint of harpoon and lance; from igip, he throws it off.

From Project Gutenberg

The apparatus is mounted with a ball-and-socket joint upon a wooden stand, as shown in Fig. 171.

From Project Gutenberg