Definition of Freedom of contract
A basic right reserved to the people by the Constitution (Art. I, § 10) that a state cannot violate even under sanction of direct legislative act. Springfield Fire & Marine Ins. Co. v. Holmes, D.C.Mont., 32 F.Supp. 964, 987. See also Impairing the obligation of contract; Liberty (Liberty of contract).
That's the definition of Freedom of contract in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.