What is the meaning of alliance?

noun

• The state of being allied or confederated.
  • synonyms: confederation
• A connection based on kinship or marriage or common interest.
  • usage: "the shifting alliances within a large family"; "their friendship constitutes a powerful bond between them"
  • synonyms: bond
• An organization of people (or countries) involved in a pact or treaty.
  • synonyms: coalition, alignment, alinement
• A formal agreement establishing an association or alliance between nations or other groups to achieve a particular aim.
• The act of forming an alliance or confederation.
  • synonyms: confederation