- union
- 1410, "action of joining one thing to another," from O.Fr. union (12c.), from L.L. unionem (nom. unio) "oneness, unity, a uniting," also in L. meaning "a single pearl or onion," from unus "one," from PIE *oinos (see one). Sense of "action of uniting into one political body" is attested from 1547. Meaning "group of people or states" is from 1660. Short for trade union, it is recorded from 1833. U.S. political sense is attested from 1775; used especially during the Civil War, in ref. to the remainder of the United States after the Southern secession. Unionize "make into a union" is attested from 1841.