Real Dictionary

ransom
variable noun: A ransom is the money that has to be paid to someone so that they will set free a person they have kidnapped.
verb: If you ransom someone who has been kidnapped, you pay the money to set them free.

Ransom in American English
John Crowe (kroʊ ) 1888-1974; U.S. poet & critic
the redeeming or release of a captive or of seized property by paying money or complying with other demands
to obtain the release of (a captive or property) by paying the demanded price
noun: the redemption of a prisoner, slave, or kidnapped person, of captured goods, etc., for a price
transitive verb: to redeem from captivity, bondage, detention, etc., by paying a demanded price

ransom in British English
noun: John Crowe. 1888–1974, US poet and critic
noun: the release of captured prisoners, property, etc, on payment of a stipulated price