1. The state of being allied; the act of allying or uniting; a union or connection of interests between families, states, parties, etc, especially between families by marriage and states by compact, treaty, or league; as, matrimonial alliances; an alliance between church and state; an alliance between France and England.
2. Any union resembling that of families or states; union by relationship in qualities; affinity. The alliance of the principles of the world with those of the gospel. (c. J. Smith) The alliance . . . Between logic and metaphysics. (Mansel)
3. The persons or parties allied.