/sin'ahr throh"sis/ , n. , pl. synarthroses /-seez/ . Anat.
immovable articulation; a fixed or immovable joint; suture.
[ 1570-80; synárthrosis, equiv. to synarthro- (var. s. of synarthroûsthai to be joined by articulation, equiv. to syn- SYN- + árthro ( n ) joint + -esthai inf. suffix) + -sis -SIS ]