A feudal subject is someone who is bound to a lord or master in a hierarchical system of land ownership and social class. A SERF, which is a four-letter word, is a peasant farmer who is bound to the land and obligated to provide labor and services to the lord of the manor. A LIEGE, which is a five-letter word, is a feudal lord or vassal who has a mutual obligation of loyalty to a higher lord or monarch.