Gekokujo ("the low overturning the high," a term used to describe retainers overthrowing their lords) describes situations in Japanese history that occur when a person of lower rank overthrows a superior either politically or militarily, and then supplants the superior's position in society.
下剋上/下克上（げこくじょう）とは、日本史において下位の者が上位の者を政治的、軍事的に打倒して身分秩序を侵す行為をさす。