- the growing together, or the fixed or nearly fixed union, of bones, as that of the two halves of the lower jaw in humans or of the pubic bones in the anterior part of the pelvic girdle.
- a line of junction or articulation so formed.
- a growing together of parts or structures, such as two bony surfaces joined by an intermediate layer of fibrous cartilage
- a line marking this growing together
- an abnormal adhesion of two or more parts or structures
