Definition from Nolo’s Plain-English Law Dictionary

1) As a noun, money paid to, or demanded by, someone in exchange for the release of a kidnapped person or stolen property. 2) As a verb, ransom may refer to either end of the transaction -- that is, it may mean to demand payment for release of a person held captive, or it may mean to pay money in exchange for the release of the person held captive.

Definition provided by Nolo’s Plain-English Law Dictionary.