- The process of joining two or more entities into a single entity
- An entity made up by combining its members or constituent parts
- An alliance established by separate individuals, nations, or entities for a shared purpose
- A form of government created when independent units surrender their main powers to a newly formed or pre-existing whole, as in the formation of a country
- The two companies formed a union to create a more robust business model.
- Workers joined the union to better protect their rights and seek fair wages.
- Three countries formed a union to strengthen their defenses against potential threats.