The Collaborative International Dictionary
Diarthrosis
Diarthrosis \Di`ar*thro"sis\, n. [NL., fr. Gr. ?, fr. ? to joint, articulate; dia` through, asunder + ? to fasten by a joint, 'a`rqron joint.] (Anat.) A form of articulation which admits of considerable motion; a complete joint; abarticulation. See Articulation.
Wiktionary
diarthrosis
n. (context anatomy English) A joint that can move freely in various planes
WordNet
diarthrosis
n. a joint so articulated as to move freely [syn: synovial joint, articulatio synovialis]
[also: diarthroses (pl)]