Tamper Definition: To interfere improperly or in violation of the law such as to tamper with a document. Related Terms: Jury Tampering In the United States v Polonio, Justice James Alger Fee of the District Court (Oregon) reiterated these words to describe the word tamper: "To meddle so as to alter a thing; especially to make corrupting or perverting changes, as to tamper with a document or a text; to interfere improperly." Similarly, in US v Tomicich, the statute at issue used but did not define the term tamper. Justice Goodrich of the District Court (Pennsylvania), adopted the same words iterated in US v Poponio but added: "... to meddle; to busy oneself rashly; to try trifling or foolish experiments...." REFERENCES: United States v. Polonio, 77 F. Supp. 768 (1941) United States v. Tomicich, 41 F. Supp. 33 (1941) Categories & Topics: Criminal Law Dictionary Find you are constantly looking up definitions? Try our search provider (works in most modern browsers) If you find an error or omission in Duhaime's Legal Dictionary, or if you have legal term suggestion, we'd love to hear from you!