Šeimynykštis (plural: šeimynykščiai) was a class of patriarchal slaves, who did the same job and lived under the same conditions as his master and family, in the early Grand Duchy of Lithuania.
Unlike kaimynas, šeimynykštis did not rent land and earn their living independently.
[2] Rather, they were members of the noble's household (the term is related to the word šeima – family).
[3] By the end of the 16th century, when Wallach reform established full serfdom in Lithuania, few šeimynykščiai were left as they merged with other classes of serfs.
[5] Šeimynykščiai were important in the early stages of feudalism (13th – mid 14th centuries) as they helped to differentiate peasants from large landowners, the future nobles.