noun
disloyal retainer; treacherous subject
Historical term for a vassal or minister who betrays their lord or country; often used in contexts of feudal loyalty.
奸臣が主君を裏切った。
The disloyal retainer betrayed his lord.
歴史書には奸臣の名が記されている。
The names of treacherous subjects are recorded in the history books.
忠臣 means 'loyal retainer', the opposite of 奸臣.
Compound of 奸 (kan, 'wicked, treacherous') and 臣 (shin, 'retainer, subject'). The exact historical derivation is uncertain.