Source : Webster's Revised Unabridged Dictionary (1913)

Anchylosis \An`chy*lo"sis\, Ankylosis \An`ky*lo"sis\, n. [NL.,
   fr. Gr. ?, fr. ?, fr. ? to crook, stiffen, fr. ? crooked: cf.
   F. ankylose.]
   1. (Med.) Stiffness or fixation of a joint; formation of a
      stiff joint. --Dunglison.

   2. (Anat.) The union of two or more separate bones to from a
      single bone; the close union of bones or other structures
      in various animals.

Ankylosis \An`ky*lo"sis\, n.
   Same as {Anchylosis}.

Source : WordNet®

ankylosis
     n : abnormal adhesion and rigidity of the bones of a joint [syn:
          {anchylosis}]