Origin: 1250–1300; ME
aliance < OF, equiv. to
ali(
er) to
ally +
-ance -ance 
Synonyms:
1. association; coalition, combination, bloc; partnership; affiliation. Alliance, confederation, league, union all mean the joining of states for mutual benefit or to permit the joint exercise of functions. An alliance may apply to any connection entered into for mutual benefit. League usually suggests closer combination or a more definite object or purpose. Confederation applies to a permanent combination for the exercise in common of certain governmental functions. Union implies an alliance so close and permanent that the separate states or parties become essentially one. 2. pact, compact.
[uh-lahy-uh