Fusion, or synthesis, is the process of combining two or more distinct entities into a new whole. Fusion may also refer to: Science and technology. Physics. Nuclear fusion, multiple atomic nuclei combining to form one or more different atomic nuclei and subatomic particles. Fusion power, power generation using controlled nuclear fusion reactions. Cold fusion, a hypothesized type of nuclear reaction that would occur at or near room temperature. Heat fusion, a welding process for joining two pieces of a thermoplastic material. Melting, or transitioning from solid to liquid form.
https://en.wikipedia.org/wiki/Fusion