What is Compact?

Legal Definition
Contracts. In its more general sense, it signifies an agreement. In its strict sense, it imports a contract between parties, which creates obligations and rights capable of being enforeed, and contemplated as such between the parties, in their distinct and independent characters. Story, Const. B. 3, c. 3; Rutherf. Inst. B. 2, c. 6, 1. 2. The constitution of the United States declares that " no state shall, without the consent of congress, enter into agreement or compact with another state, or with a foreign power." See 11 Pet: 1; 8 Wheat. 1 Bald. R. 60; 11 Pet. 185.
-- Bouviers Law Dictionary
Legal Definition
An agreement or contract Usually applied to conventions between nations or sovereign states. A compact is a mutual consent of parties concerned respecting some property or right that is the object of the stipulation, or something that is to be done or forborne. Chesapeake & O. Canal Co. v. Baltimore & O. It. Co.., 4 Gill & J. (Md.) L The terms "compact" and "contract" are synonymous. Green v. Biddle, 8 Wheat 1, 92, 5 In Ed. 547.
-- Black's Law Dictionary
Legal Definition
A contract; a treaty.
-- Ballentine's Law Dictionary