noun
loyal retainer; loyal subject
Refers to a vassal or subject who is faithful to their lord or ruler, often in a historical or feudal context. Can also be used figuratively for a devoted follower.
彼は主君に仕える忠臣だった。
He was a loyal retainer who served his lord.
忠臣蔵は有名な物語
Chushingura is a famous story.