fused

Fused is the past participle of fuse and is used as an adjective to describe two or more things that have been joined or blended into a single entity, typically through melting, heating, or other bonding processes. The sense is common across science, engineering, and craft, applying to materials, joints, and structures formed by fusion.

In materials science and glassmaking, fused refers to substances produced by melting raw materials and allowing them to solidify. Fused silica or fused quartz, for example, are high-purity silicon dioxide glasses created by melting silica and removing impurities; they are valued for low thermal expansion and high optical clarity. Fused glass describes glass formed by heating and bonding glass pieces or frit together in a kiln, a technique widely used in art and jewelry. In metallurgy and ceramics, fusion welding and similar processes join parts by melting their surfaces so that they fuse into a continuous piece.

In electrical engineering, a fuse is a protective device containing a fusible element that melts when current exceeds its rating, interrupting the circuit to prevent damage or fire. Devices or circuits described as fused have incorporated such protective links, and the term fused can be used to indicate that a fuse has melted or that a fused connection exists.

In chemistry and biology, fused also appears in descriptions of fused-ring systems in organic compounds, where adjacent rings share atoms and form a single, extended structure. The term thus covers both practical manufacturing contexts and structural descriptions in science.