Which type of joint is characterized by being immovable?

The characteristic of being immovable is most accurately associated with fibrous joints. These types of joints are connected by dense connective tissue, which primarily consists of collagen fibers. This dense connective tissue provides both stability and strength, effectively limiting movement between the bones.

In the human body, examples of fibrous joints include the sutures of the skull, where the bones are tightly bound together, allowing very little to no movement. This is essential for maintaining the structural integrity of the skull as it protects the brain.

Other joint types, such as synovial joints, amphiarthroses, and cartilaginous joints, allow varying degrees of movement. Synovial joints are the most mobile type, while cartilaginous joints permit limited movement, and amphiarthroses allow slight movement but are not immovable. Thus, the defining characteristic of immobility is best represented by fibrous joints.