fourth amendment
Fourth Amendment. The constitutional amendment, ratified with the Bill of Rights in 1791, prohibiting unreasonable searches and seizures and the issuance of warrants without probable cause. See PROBABLE CAUSE. [Cases: Searches and Seizures 23. C.J.S. Searches and Seizures §§ 3, 5, 9–12, 14–15, 24, 29–30, 32, 34, 47–48, 102.]