n.
农役租佃

Socage \Soc"age\, n.[From {Soc}; cf. LL. socagium.] (O.Eng. Law)
A tenure of lands and tenements by a certain or determinate
service; a tenure distinct from chivalry or knight's service,
in which the obligations were uncertain. The service must be
certain, in order to be denominated socage, as to hold by
fealty and twenty shillings rent. [Written also {soccage}.]

Note: Socage is of two kinds; {free socage}, where the
services are not only certain, but honorable; and
{villein socage}, where the services, though certain,
are of a baser nature. --Blackstone.