Fusion means the joining together of separate things to create something new. When two things fuse, they combine so completely that they become a single entity.

In science, fusion describes what happens when atomic nuclei (the centers of atoms) combine to form a heavier nucleus, releasing enormous amounts of energy. This process powers the sun and all stars. Scientists are working to create controlled fusion reactions on Earth because fusion energy could provide nearly limitless, clean power. Unlike splitting atoms apart (called fission), fusion pushes them together under extreme heat and pressure.

You'll also encounter fusion in everyday contexts. Fusion cuisine combines cooking styles from different cultures, like when a chef creates tacos with Korean barbecue. Jazz fusion blends jazz with rock or other musical styles. When a doctor talks about spinal fusion, they mean a surgery that joins vertebrae together permanently.

Whether describing atoms in the sun's core, musical styles, or ideas blending into something fresh and original, fusion always involves distinct elements combining into an integrated whole.