blackmail, in law, exaction of money from another by threat of exposure of criminal action or of disreputable conduct. The term was originally used for the tribute levied until the 18th cent. upon the inhabitants of the Scottish border to provide immunity from raids by Scottish bands. Statutes often treat blackmail as a form of extortion.

Unlawful exaction of money or property through intimidation or undue exercise of authority. It may include threats of physical harm, criminal prosecution, or public exposure. Some forms of threat, especially those made in writing, are occasionally singled out for separate statutory treatment as blackmail. Seealso bribery.

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