Thrall

A Thrall is a bound servant in Ironborn culture. They are people kidnapped during raids and employed for tasks such as agriculture and mining, which the ironborn despise. Like Salt wives, they have a low status in ironborn society.

In the books
A thrall isn't quite the same thing as a slave, as the ironborn raiders don't believe in "slavery" as such. Thralls are captured in raids, by "paying the iron price", but cannot be bought or sold like animals. The children of a thrall are considered free and may become raiders so long as they convert to the religion of the Drowned God.