noun
plural unions
[count] :an organization of workers formed to protect the rights and interests of its members
[noncount] :an act of joining two or more things together
[singular] :a group of states or nations that are ruled by one government or that agree to work together
the Union
the United States
The State of the Union address is a yearly speech given by the U.S. President to Congress and the people to tell them about important things that are affecting the country.
the group of northern states that supported the federal government during the American Civil War
[count] :an organized group of people, businesses, etc., that have the same purpose or interest
formal :the act of getting married or of causing two people to be married [noncount]
[count, noncount] formal :the activity or an act of having sex