ankylosis

/AE1 NG K Y AH0 L OW1 S IH0 S/
noun
  1. 1

    The growing together of bones to form a single unit.

  2. 2

    The stiffening of a joint as the result of such abnormal fusion.

  3. 3

    An onset of stiffness or inflexibility.

Source: https://en.wiktionary.org/wiki/ankylosis