• Yang - Yang is the light, active, positive and masculine principle in Chinese philosophy
• Yemaya - Yoruban Mother Goddess, Goddess of the Ocean
• Yggdrasil - One of the best known Tree of Life symbols. It unites all existence from the Underworld, to the Physical world.
• Yin - Yin is the dark, passive, negative, feminine principle in Chinese philosophy.
• Yule - One of the Wiccan eight holy days, also called Winter Solstice; celebrated on December 21st of each year.
• Yule Log - The traditional log burned at Christmas ceremonies which most likely came from a pagan tradition for Yule celebration.
• Zodiac - The arc of the sky from the horizon, along which the Sun travels, making 360 degrees, is divided into twelve sectors of thirty degrees each, each sector corresponding to an astrological sign and with a specific character and significance of its own. 
•  Zodiacal Age - Period of time that is ruled (and thus characterized) by one of the signs of the Zodiac. The most common theory of the Zodiacal Ages is the Correllian theory. According to the Correllian calendar, a Zodiacal Age lasts for 1600 years, (four sets of four hundred years) and the present age is the Age of Aquarius begun as of the year 2001 AD. The Piscean Age (completed as of the end of 1999) will not come again until all the other eleven Zodiacal Ages have been completed (about 17,600 years).
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