What does anchylosis or ankylosis mean?
The definition of anchylosis and ankylosis
An`chy*lo”sis, An`ky*lo”sis, n.
Etym: [NL., fr. Gr. 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.