from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A synovial 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. Also called enarthrosis.
- n. A joint, as in a mechanical device, that permits rotary movement in all directions through the movement of a ball in a socket. Also called ball joint.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. 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.
Sorry, no etymologies found.