Unfused

Unfused is an adjective meaning not fused or not united by fusion. In general, it describes separate components that have not been permanently joined into a single mass, either because fusion has not occurred yet or because remaining separate is appropriate in the given context.

In biology and medicine, unfused is used to describe developmental states. For example, an infant’s skull bones are separated by sutures and fontanelles that are unfused, allowing growth of the brain. During childhood, growth plates at the ends of long bones remain unfused to permit lengthening; these epiphyseal plates eventually fuse when growth ends. The degree of fusion can be diagnostically relevant, and premature fusion can indicate medical concerns in some cases.

In materials science and manufacturing, unfused may describe materials or joints that have not been melted or bonded. In glassmaking, unfused glass refers to glass that has not been heated to a viscous state to form a single piece; in welding and soldering contexts, a joint is unfused if the materials have not yet fused.

Other uses span disciplines, including botany, geology, and mechanical engineering, where unfused denotes components that remain separate rather than fused into a single unit. Because unfused means different things across fields, it is typically defined by the specific discipline and context in which it appears.