Definition from Wiktionary, the free dictionary
Alternative forms 
- (uncountable) The state of being allied.
- (countable) The act of allying or uniting.
- (countable) A union or connection of interests between families, states, parties, etc., especially between families by marriage and states by compact, treaty, or league.
- (countable) 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.
- (with the definite article) The persons or parties allied.
- (union by relationship in qualities): connection, affinity, union
- (act of allying): union
- (persons or parties allied): coalition, league, confederation, team (informal)
Related terms 
state of being allied
union resembling that of families or states
persons or parties allied
treaty between nations
- alliance at OneLook Dictionary Search
- alliance in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913
alliance f (plural alliances)