| Union | |
| 1. n. The 0-10-2 locomotive wheel arrangement. Derived from the name of the only U.S. company to use that configuration. | |
| 2. n. The act of uniting or joining two or more things into one. | |
| 3. n. The state of being united or joined. | |
| 4. n. 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. | |
| 5. n. A trade union; a workers' union. | |
| 6. n. An association of students at a university for social and/or political purposes; also in some cases a debating body. | |
| 7. n. A joint or other connection uniting parts of machinery, such as pipes. | |
| 8. n. (set theory) The set containing all of the elements of two or more sets. | |
| 9. n. The act or state of marriage. | |
| 10. n. (archaic, euphemistic) Sexual intercourse. | |
| 11. n. (programming) A data structure that can store any of various types of item, but only one at a time. | |
| 12. n. (now rare, archaic) A large, high-quality pearl. | |
| 13. n. (historical) An affiliation of several parishes for joint support and management of their poor; also the jointly-owned workhouse. | |
| 14. v. To combine sets using the union operation. | |
