noun
rebellious retainer; vassal who rebels
Historical term for a retainer or vassal who turns against their lord. Used in contexts of feudal rebellion.
戦国時代には、多くの反臣が主君に背いた。
During the Warring States period, many rebellious retainers turned against their lords.
Compound of 反 (rebel, oppose) and 臣 (retainer, vassal). The alternate form 叛臣 uses 叛, a variant character also meaning 'rebel'.