An Alliance

1. (uncountable) The state of being allied.
2. (countable) The act of allying or uniting.
3. (countable) A union or connection of interests between families, states, parties, etc., especially between families by marriage and states by compact, treaty, or league.
4. (countable) Any union resembling that of families or states; union by relationship in qualities; affinity.
5. (with the definite article) The persons or parties allied.

Synonyms

• (union by relationship in qualities): connection, affinity, union
• (act of allying): union
• (persons or parties allied): coalition, league, confederation, team (informal)