The full Moon shares the symbolism of the circle as an image of wholeness and strength. The Chinese associate it with the essence of Yin and the feminine; to Buddhists it represents spiritual power. The Harvest Moon (a full Moon near the September equinox) symbolizes agricultural fertility. The word "lunatic" comes from the Latin for full Moon was thought to worsen lunacy and is association
"Signs & Symbols" - An illustrated guide to their origins and meanings.