Final answer:
A monarchy is a form of government in which a single individual, either a king or queen, holds supreme power over a kingdom or empire until they die or abdicate the throne.
Step-by-step explanation:
A monarchy is a form of government in which supreme power is held by a single individual known as a monarch. This individual, either a king or queen, reigns over a kingdom or empire until they die or abdicate the throne. Monarchs often claim their right to rule through hereditary succession or divine appointment. In modern times, many monarchies have become ceremonial remnants of tradition, with monarchs serving as figureheads while abiding by the laws of a constitution.