Adjective union has 2 senses
  1. Union, Federal - being of or having to do with the northern United States and those loyal to the Union during the Civil War; "Union soldiers"; "Federal forces"; "a Federal infantryman"
    Antonym: southern (indirect, via northern)
  2. union - of trade unions; "the union movement"; "union negotiations"; "a union-shop clause in the contract"
    nonunion, open, unorganized, unorganised, nonunionized, nonunionised
,Noun union has 11 senses
  1. union, labor union, trade union, trades union, brotherhood - an organization of employees formed to bargain with the employer; "you have to join the union in order to get a job"
    --1 is a kind of organization, organisation
    --1 is a part of labor movement, trade union movement, labor
    --1 has particulars:
     industrial union, vertical union; craft union; company union; Industrial Workers of the World, IWW, I.W.W.
    Derived forms: verb unionize1, verb unionize2
  2. Union, North - the United States (especially the northern states during the American Civil War); "he has visited every state in the Union"; "Lee hoped to detach Maryland from the Union"; "the North's superior resources turned the scale"
    --2 is a kind of United States, United States of America, America, US, U.S., USA, U.S.A.
    --2 has parts: free state
  3. coupling, mating, pairing, conjugation, union, sexual union - the act of pairing a male and female for reproductive purposes; "the casual couplings of adolescents"; "the mating of some species occurs only in the spring"
    --3 is a kind of sexual activity, sexual practice, sex, sex activity
    --3 has particulars:
     assortative mating; disassortative mating; hybridization, hybridisation, crossbreeding, crossing, cross, interbreeding, hybridizing; inbreeding; servicing, service
  4. union, unification - the state of being joined or united or linked; "there is strength in union"
    --4 is a kind of state
    Antonyms: separation
    --4 has particulars:
     coalition, fusion; connection, link, connectedness; junction, conjunction, conjugation, colligation; association; marriage; syncretism
  5. marriage, matrimony, union, spousal relationship, wedlock - the state of being a married couple voluntarily joined for life (or until divorce); "a long and happy marriage"; "God bless this union"
    --5 is a kind of marital status
    --5 has particulars:
     bigamy; common-law marriage; endogamy, intermarriage, inmarriage; exogamy, intermarriage; marriage of convenience; misalliance; monandry; monogamy, monogamousness; open marriage; polygamy; sigeh
  6. union, conglutination - healing process involving the growing together of the edges of a wound or the growing together of broken bones
    --6 is a kind of healing
  7. union - a political unit formed from previously independent people or organizations; "the Soviet Union"
    --7 is a kind of
    political unit
    --7 has particulars:
     confederation, confederacy, federation; enosis; league; customs union
  8. union, sum, join - a set containing all and only the members of two or more given sets; "let C be the union of the sets A and B"
    --8 is a kind of set
    --8 has particulars: direct sum
  9. union - the occurrence of a uniting of separate parts; "lightning produced an unusual union of the metals"
    --9 is a kind of
    happening, occurrence, natural event
    --9 has particulars:
     amphimixis; fusion, merger, unification; combining, combine
  10. union - a device on a national flag emblematic of the union of two or more sovereignties (typically in the upper inner corner)
    --10 is a kind of
  11. union, unification, uniting, conjugation, jointure - the act of making or becoming a single unit; "the union of opposing factions"; "he looked forward to the unification of his family for the holidays"
    --11 is a kind of combination, combining, compounding
    Antonyms: disunion
    --11 has particulars:
     coalescence, coalescency, coalition, concretion, conglutination; reunion, reunification; tribalization, tribalisation; umbrella
    Derived form: verb unite2