Serf - Peasant burdened with week-work, merchet, tallage, and other obligations; bondman, villein. A semi-free peasant who worked his lord's demesne and paid him certain dues in return for the use of land, the possession (not owndership) of which was heritable. These dues, usually called corevee, were almost all in the form of labor on the lord's land. Generally this averaged to three days a week. Generally subdivided into classes called cottagers, small holders, or villeins although the latter originally meant a free peasant who was burdened with additional rents and services.