Hey you! Yes, you! Thank you for adding beauty to the world!
Definitions of vasal:
adjective: Relating to a vessel (of the body)
noun: (rare) Alternative spelling of vassal [(historical) 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.]
verb: (rare) Alternative spelling of vassal [(transitive) To treat as a vassal or to reduce to the position of a vassal; to subject to control; to enslave.]