[ ˌsɪnα:'θrəʊsɪs ]
■ noun ( plural synarthroses -si:z ) Anatomy an immovable joint between bones connected by fibrous tissue (e.g. the sutures of the skull).
Origin
C16: from mod. L., from Gk sunarthrōsis , from sun- 'together' + arthrōsis 'jointing' (from arthron 'joint').