union

noun \ ˈyün-yən \

Definition of union

1 a :an act or instance of uniting or joining two or more things into one: such as

(1) :the formation of a single political unit from two or more separate and independent units

(2) :a uniting in marriage; also :sexual intercourse

(3) :the growing together of severed parts

b :a unified condition :combination, junction

a gracious union of excellence and strength

2 :something that is made one :something formed by a combining or coalition of parts or members: such as

a :a confederation of independent individuals (such as nations or persons) for some common purpose

b (1) :a political unit constituting an organic whole formed usually from units which were previously governed separately (such as England and Scotland in 1707) and which have surrendered or delegated their principal powers to the government of the whole or to a newly created government (such as the U.S. in 1789)

(2) capitalized :the federal union of states during the period of the American Civil War

c capitalized :an organization on a college or university campus providing recreational, social, cultural, and sometimes dining facilities; also :the building housing such an organization

d :the set of all elements belonging to one or more of a given collection of two or more sets — called also join, sum

e :labor union

3 a :a device emblematic of the union of two or more sovereignties borne on a national flag typically in the upper inner corner or constituting the whole design of the flag

b :the upper inner corner of a flag

4 :any of various devices for connecting parts (as of a machine); especially :a coupling for pipes or pipes and fittings

See union defined for English-language learners

See union defined for kids

Examples of union in a Sentence

She joined the teachers' union.
An embryo is created through the union of sperm and egg.
a perfect union of Eastern and Western music

Recent Examples of union from the Web

The donations reflects contributions from any individuals who list their employer as an oil and gas firm as well as as corporations and unions who donate from their treasuries.

— amy sherman, miamiherald, "Marco Rubio heckled over oil and gas donations in Senate race," 30 Aug. 2017
The police union sued, claiming the board was unconstitutional, tying it up in court.

— matthew glowicki, The Courier-Journal, "If Louisville's police watchdog group is a bulldog that 'cannot bite,' is it relevant?," 28 Aug. 2017
And if all goes well, Jorah, who has long been fighting the good fight on behalf of his queen, may one day fight alongside any heirs that come out of this union.

— peggy truong, Cosmopolitan, "What You Might Have Missed About Daenerys and Her Line of Succession on Game of Thrones," 21 Aug. 2017
Reimagine yourself as the eclipse appears in your own sign Dive In: A divine union.

— rebecca gordon, Harper's BAZAAR, "Your August 2017 Solar Eclipse Horoscope," 21 Aug. 2017
Union drives would go better, as employers stopped being able to threaten workers with deportation.

— t.a. frank, The Hive, "The Democratic Case for Restricting Immigration," 9 Aug. 2017
Stalled contract talks with the Chicago New Car Dealer Committee, which represents the dealership owners, started in June, according to the union's website.

— erin hegarty, Naperville Sun, "Mechanics on strike at 9 Naperville car dealerships," 2 Aug. 2017
Some students headed outside to practice using an ATM, others worked at a computer to activate their online accounts, while others downloaded the credit union’s mobile app.

— priscella vega, Burbank Leader, "High school students learn financial responsibility through Burbank City Federal Credit Union," 25 July 2017
Meanwhile some ministers think the customs union should be rethought.

— The Economist, "The six flavours of Brexit," 22 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'union.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of union

Middle English, from Anglo-French, from Late Latin union-, unio oneness, union, from Latin unus one — more at one

NEW! Time Traveler

First Known Use: 15th century

See Words from the same year

union Synonyms

Near Antonyms

detachment, divorcement, separation, severance

Other Business Terms

amortize, caveat emptor, clearinghouse, divest, due diligence, emolument, green-collar, marque, overhead, perquisite

union

adjective

Definition of union

:of, relating to, dealing with, or constituting a union; especially, capitalized :of, relating to, or being the side favoring the Union in the American Civil War

Union troops

First Known Use of union

1634

UNION Defined for English Language Learners

union

noun

Definition of union for English Language Learners

: an organization of workers formed to protect the rights and interests of its members
: an act of joining two or more things together
: a group of states or nations that are ruled by one government or that agree to work together

UNION Defined for Kids

union

noun \ ˈyün-yən \

Definition of union for Students

1 :an act or instance of uniting or joining two or more things into one

The river is formed by the union of two tributaries.

2 :something (as a nation) formed by a combining of parts or members

3 capitalized :the United States

4 capitalized :the group of states that supported the United States government in the American Civil War

5 :a device for connecting parts (as pipes)

6 :labor union

Union

adjective

Definition of Union for Students

:relating to the group of states that supported the United States government in the American Civil War

Union soldiers

Medical Dictionary

union

noun \ ˈyü-nyən \

medical Definition of union

:an act or instance of uniting or joining two or more things into one: as

a :the growing together of severed parts

union of a fractured bone

b :a chemical combination :bond

c :the joining of two germ cells in the process of fertilization

Law Dictionary

union

noun

legal Definition of union

1 :an act or instance of uniting or joining two or more things into one; especially :the formation of a single political unit from two or more separate and individual units

2 :something that is made one :something formed by a combining or coalition of its members: as

a :a confederation of independent individuals (as nations or persons) for some common purpose

b :a political unit constituting an organic whole formed usually from previously independent units (as England and Scotland in 1707) which have surrendered their principal powers to the government of the whole or to a newly created government (as the U.S. in 1789)

c :labor union