A salt wife is a bound concubine in ironborn culture. They are usually the women kidnapped during raids. An ironborn may keep several salt wives, but only one "rock wife", which is of ironborn origin. "Salt wives" truly are concubines in all but name, and an ironborn's children by them are considered bastards. Given that they aren't paid, salt wives aren't considered prostitutes.
Salt wives have a low status in ironborn society, similar to thralls. Salt wives don't toil in the fields and mines as thralls do, but they do serve as concubines.
In the booksEdit
A salt wife isn't quite the same thing as a slave, as even the ironborn raiders don't believe in "slavery" as such. The difference is that a salt wife cannot be bought and sold, or traded: an ironborn may only keep salt wives that he has personally captured in raids, as this is considered "paying the iron price". Also, the ironborn generally look down on selling slaves, as they still think of their captives as human beings, albeit on the bottom rung of society, and not animals to be sold. The children of a salt wife are free so long as they convert to the religion of the Drowned God.