乱らん臣しん

noun

traitor; rebellious vassal

Historical term for a vassal or minister who betrays their lord or causes disorder in the realm. Often used in contexts of feudal loyalty and rebellion.

• 彼かれは主しゅ君くんに背そむいた乱らん臣しんとして歴れき史しに名なを残のこした。

  He went down in history as a traitor who betrayed his lord.