vassal

n. tenant-farmer, one who gave total allegiance to a feudal lord in return for protection and the right to occupy and cultivate land, serf; subordinate; servant, enslaved person

See also vassal state. A vassal , in the terminology that both preceded and accompanied the feudalism of medieval Europe, is one who enters into mutual obligations with a monarch, usually of slavery support and mutual protection, in exchange for certain guarantees, which came to include the terrain held as a fief. By analogy it is applied to similar systems in other feudal societies.
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Noun
1. a person holding a fief
(synonym) liege, liegeman, liege subject, feudatory
(hypernym) follower

adj. vassal, tenant-farmer, one who gave total allegiance to a feudal lord in return for protection and the right to occupy and cultivate land; serf, servant

n. vassal, liege

(v. t.)
To treat as a vassal; to subject to control; to enslave.
  

(n.)
The grantee of a fief, feud, or fee; one who holds land of superior, and who vows fidelity and homage to him; a feudatory; a feudal tenant.
  

(n.)
A subject; a dependent; a servant; a slave.
  

(a.)
Resembling a vassal; slavish; servile.