1. any payment extorted by intimidation, as by threats of injurious revelations or accusations.
2. the extortion of such payment: He confessed rather than suffer the dishonor of blackmail.
3. a tribute formerly exacted in the north of England and in Scotland by freebooting chiefs for protection from pillage.
–verb (used with object)
4. to extort money from (a person) by the use of threats.
5. to force or coerce into a particular action, statement, etc.: The strikers claimed they were blackmailed into signing the new contract.