J.B.
It means "adopted" -in the sense that the baby's mother is not available and there's probably not a wet nurse around, so the baby would have to take some type of animal milk or mixture from the beginning. Animals that are hand reared are raised from infancy by humans instead of their biological mothers. These days we have all sorts of fancy formulas, bottles, precise measurements and what not -but in the 16th century infant mortality was extremely high in the BEST of circumstances, so infants with no adequate breast milk to partake of were in dire shape.