syn·ar·thro·di·a 
(sĭn′är-thrōdē-ə)
(sĭn′är-thrōdē-ə)n. pl. syn·ar·thro·di·ae (-dē-ē′)
See synarthrosis.
[SYN- + Greek arthrōdia, a kind of articulation (from arthrōdēs, well-jointed, from arthron, joint; see SYNARTHROSIS).]
syn′ar·throdi·al adj.
syn′ar·throdi·al·ly adv.