From Middle English unyoun, from Old French union, from Late Latin ūniō, from Latin ūnus.

• IPA: /ˈjuː.njən/, /ˈjuː.ni.ən/

union

1. (countable) The act of uniting or joining two or more things into one.

   Synonyms: junction, coalition, combination

   Antonyms: nonunion

2. (countable) The state of being united or joined; a state of unity or harmony.

   Antonyms: nonunion

3. (countable) That which is united, or made one; something formed by a combination or coalition of parts or members; a confederation; a consolidated body; a league.
4. (countable) A trade union; a workers' union.
   • 1918, W[illiam] B[abington] Maxwell, chapter XXII, in The Mirror and the Lamp, Indianapolis, Ind.: The Bobbs-Merrill Company, →OCLC ↗:

     In the autumn there was a row at some cement works about the unskilled labour men. A union had just been started for them and all but a few joined. One of these blacklegs was laid for by a picket and knocked out of time.

5. (countable) An association of students at a university for social and/or political purposes; also in some cases a debating body.
6. (countable) A joint or other connection uniting parts of machinery, such as pipes.
7. (countable, set theory) The set containing all of the elements of two or more sets.
8. (countable) The act or state of marriage.
9. (uncountable, archaic, euphemistic) Sexual intercourse.
10. (countable, programming) A data structure that can store any of various types of item, but only one at a time.
11. (countable, now rare, archaic) A large, high-quality pearl.
    • 1624, Democritus Junior [pseudonym; Robert Burton], The Anatomy of Melancholy: […], 2nd edition, Oxford, Oxfordshire: […] John Lichfield and James Short, for Henry Cripps, →OCLC ↗, partition II, section 3, member 3:

      Nonius the senator hath a purple coat as stiff with jewels as his mind is full of vices; rings on his fingers worth 20,000 sesterces, and […] an union in his ear worth an hundred pounds' weight of gold […]

    • c. 1599–1602 (date written), William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act V, scene ii]:

      And in the cup an union shall he throw, Richer than that which four successive kings In Denmark's crown have worn.

12. (historical) An affiliation of several parishes for joint support and management of their poor; also the jointly-owned workhouse.

• French: union
• German: Vereinigung, Union, Verein, Verband
• Italian: unione
• Portuguese: união, junção
• Russian: сою́з
• Spanish: unión

• French: groupement
• German: Vereinigung, Union
• Portuguese: união
• Russian: сою́з
• Spanish: unión

• French: connexion
• Russian: му́фта

• French: réunion
• German: Vereinigung, Vereinigungsmenge
• Italian: unione
• Portuguese: união
• Russian: объединение множество
• Spanish: unión

• French: mariage
• German: Ehe
• Portuguese: matrimónio (Portugal), matrimônio (Brazil)
• Russian: сою́з

• French: accouplement, copulation, fornication
• German: Vereinigung
• Portuguese: sexo
• Russian: сноше́ние

• French: union
• Russian: объедине́ние

union (unions, present participle unioning; simple past and past participle unioned)

1. (set theory) To combine sets using the union operation.

union

1. Belonging to, represented by, or otherwise pertaining to a labour union.

   Synonyms: unionized

   Antonyms: nonunion

   Actors have to be union to get work here.

2. (India) federal.

   The union government of India

• IPA: [uˈni̯oːn]

union (plural unions)

1. The 0-10-2 locomotive wheel arrangement.
2. The canton of the United States flag: the portion of the flag containing stars on a blue background.

1. (US, with determiner, dated, especially 19th century) The United States of America.

   threats to secede from the Union

2. (US, with determiner, historical) Those of the United States that did not secede at the time of the Civil War (of the United States of America).

   Union troops at Gettysburg

3. (with determiner, historical) The Soviet Union: the proper noun Union is the standard English translation of the proper noun Союз, and all-Union is the standard English translation of всесоюзный.

   throughout the Union, but nowhere more so than at the Center [Moscow]

4. (chiefly, India, with determiner, law) Alternative form of union
5. Place names:
   1. A community in Central Elgin, Elgin County.
   2. A barangay in Ubay, Bohol.
   3. A village on the south cast of the island of Siargao.
   4. A number of places in USA:
      1. A town in Greene County, Alabama.
      2. A ghost town in Merced County, California.
      3. A former unincorporated community in Napa County, California.
      4. A small town in Tolland County, Connecticut.
      5. A village in McHenry County, Illinois.
      6. An unincorporated community in Clay, Pike County.
      7. A tiny city in Hardin County, Iowa.
      8. A home rule city in Boone County, Kentucky.
      9. A town in Knox County, Maine.
      10. A town in Neshoba County, and.
      11. A city/county seat in Franklin County, Missouri.
      12. An unincorporated community in Clark County, Missouri.
      13. A village in Cass County, Nebraska.
      14. A village/and/CDP in the town of Wakefield.
      15. A hamlet in Madison County, New York.
      16. A large town in Broome County, New York.
      17. A city in Montgomery County, and.
      18. A city in Union County, Oregon.
      19. A city/county seat in Union County, South Carolina.
      20. An unincorporated community in Floyd County, Virginia.
      21. A small town/county seat in Monroe County, West Virginia.
      22. A small town in Burnett County, Wisconsin.
      23. A small town in Door County, Wisconsin.
      24. A town/and/unincorporated community in Eau Claire County, Wisconsin.
      25. An unincorporated community in the town of Lima.
      26. A small town in Pierce County, Wisconsin.
      27. A town/and/unincorporated community in Rock County, Wisconsin.
      28. A small town in Vernon County, Wisconsin.
      29. A small town in Waupaca County, Wisconsin.
      30. A large number of townships in the USA, listed under Union Township.

Probably a variant spelling of Onion.

1. Surname.

1. (Oxon, informal) The Oxford Union (a debating society); not to be conflated with Oxford University Student Union (a students' union).