A league, or covenant; a contract between two or more persons, bodies of men or states, combined in support of each other, in some act or enterprise; mutual engagement; federal compact. The friendships of the world are oft confederacies in vice. A confederacy of princes to check innovation.

The persons, states or nations united by a league. Virgil has a whole’ confederacy against him.

In law, a combination of two or more persons to commit an unlawful act.