Socage

1. 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.
   

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.