What does union mean?
Union describes the act of joining separate people, groups, organizations, or things into one whole. In its most familiar modern sense, it names a labor or trade union: an organized body of workers that represents members in negotiations with employers. Outside that context, the word can refer to marriage, an agreement between states or institutions, or simply the condition of being united. “The union of the two departments” is therefore different from “the teachers’ union,” even though both involve joining or association. The word also has a specialized mathematical meaning: the union of two sets contains every element found in either set. Union can function as a formal verb meaning to combine or join things, although this usage is less common in everyday English. Overall, the word carries connotations of cooperation, shared membership, collective strength, and agreement, while its meaning depends heavily on context.
An organization of workers formed to protect shared interests, represent members, and bargain collectively; more broadly, an agreement, marriage, or state of being joined together.
"Members voted to join the union and elect its representatives."
The labor-union sense is dominant in modern English. Other senses, especially marriage and formal agreement, are often elevated or institutional in register.
To join or combine two or more people, organizations, or things.
"The committee proposed unioning the two research programs."
This is a formal and relatively uncommon verb in contemporary usage.
The regular plural of the noun is formed by adding -s.
"The two unions announced a joint agreement."
Union comes from the Latin unus, meaning “one,” reflecting the ancient idea of bringing separate parts into a single whole.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of union
The word entered English in the late Middle English period through French union, from Latin unio, a joining or uniting. Latin unio was derived from unus, meaning “one” or “single,” the same source behind words such as unit, unity, unite, and universal. Over time, union developed meanings covering both the process of joining and the resulting whole or association.
Related word forms
How union is actually used
In contemporary English, union most often refers to a labor or trade union. It can also sound formal or slightly traditional when describing a marriage or an agreement between states or organizations. The verb is relatively uncommon in everyday speech.