What is the origin of the world lunacy?

The Word "lunacy" originates from the Latin term "lunaticus," which means "moonstruck" or "of the moon." This association stems from ancient beliefs that the phases of the moon influenced human behavior and mental health. Historically, people thought that certain mental illnesses were linked to the moon's cycles, particularly the full moon. Over time, "lunacy" evolved to refer more broadly to irrational behavior or madness.