Meaning

noun a form of government in which the ruler is an absolute dictator (not restricted by a constitution or laws or opposition etc.)

noun dominance through threat of punishment and violence

originInherited from Middle English tirannye, from Old French tyrannie, from Medieval Latin tyrannia, tyrania, from Ancient Greek τυραννία (turannía, “tyranny”), from τύραννος (túrannos, “lord, master, sovereign, tyrant”).

Etymology from Wiktionary, CC BY-SA 3.0