n. The grantee of a fief, feud, or fee; one who keeps land of a superior, and who vows fidelity and homage to him, normally a lord of a manor; a feudatory; a feudal tenant.n. A subject; a dependant; a servant; a slave.adj. Resembling a vassal; slavish; servile.v. To treat as a vassal or to reduce to the position of a vassal; to subject to control; to enslave.v. To subordinate to someone or something.