1) Articulatio 2) Articulatio synovialis 3) Articulation 4) Joint 5) Synovial joint 1) Enarthrosis 2) Ginglymus 3) Knuckle 
• (n.) A form of articulation which admits of considerable motion; a complete joint; abarticulation. See Articulation.
(di″ahr-thro´sis) pl. diarthro´ses synovial joint. diarthrosis rotatoria a joint characterized by mobility in a rotary direction.
Di`ar·thro'sis noun [ New Latin , from Greek ..., from ... to joint, articulate; 
Type: Term Pronunciation: dī′ar-thrō′sis, -sēz Synonyms: synovial joint
(di;ar-thro;sis) A type of functionally classified joint in which the articulating bones are freely movable; also called a synovial joint.
In anatomy, diathrosis refers to that formation of joints which allows free movement.
a form of articulation that permits maximal motion, as the knee joint.