private international law
noun
The branch of law which deals with cases of private law involving a foreign element (as the fulfilment of contracts, recognition of marriages and other relationships contracted abroad, etc.), especially in determining the extent to which courts of one's own country have jurisdiction over such cases and whether the domestic or foreign law should be applied by the court to resolving the issue.
Origin
Mid 19th century; earliest use found in Joseph Story (1779–1845).