Alliance (noun)

1. A union or association formed for mutual benefit, especially between countries or organizations.
2. A relationship based on common interests or goals.

Origin:

Late middle english: from old french aliance, from alier "unite, ally", from latin alligare "bind, tie to", from ad- "to" + ligare "bind".

Examples:

1. The two countries formed an alliance.
2. The alliance between the two companies was beneficial for both.
3. The alliance will help to strengthen the country's defense.
4. He formed an alliance with other businessmen.
5. The alliance between the two countries was an important step in resolving the conflict.