The Collaborative International Dictionary of English v.0.48:

Symphysis \Sym"phy*sis\, n.; pl. Symphyses. [NL., fr. Gr. ?,
   fr. ? to make to grow together; sy`n with + ? to cause to
   grow; to grow.] (Anat.)
   (a) An articulation formed by intervening cartilage; as, the
       pubic symphysis.
   (b) The union or coalescence of bones; also, the place of
       union or coalescence; as, the symphysis of the lower jaw.
       Cf. Articulation.
       [1913 Webster]

WordNet (r) 3.0 (2006):

symphysis
    n 1: an abnormal adhesion of two or more structures
    2: a growing together of parts or structures