The meaning of the Yei symbol represents the Navajo Yei Spirit who mediates between humans and the Great Spirit. The term Yei derives from the word Yeibicheii meaning the Holy People. Navajo Yei (Yeii) spirits, or deities, are believed to control elements such as the rain, snow, wind and sun and control the night and day. Most of the Navajo deities can be either beneficial or harmful to the Earth Surface People, depending on their mood or impulse or on how they are approached. The Yei is also believed to be associated with the rainbow goddess. Depictions of Yei were commonly created on Petroglyphs and Sand Paintings.

Yei Petroglyph
The picture below are Yei Petroglyphs - drawings that have been carved in stone. Yei Spirits are usually shown carrying pine boughs, yucca strips and rattles and these items feature in Navajo Spiritual Healing ceremonies.

Yei Petroglyph

The Yei Symbol - Masked Dancers
The Navajo believed that Yei spirits could be summoned by masked dancers. The ancient Mound Builders, the Mississippians, used dances, gestures and sounds as symbolic powers and wore ceremonial clothes and carried sacred objects and weapons to symbolize their power. Masks were believed to hold spiritual powers that never left them and that the masks would identify them with the Yei spirits and activate their power. During Navajo masque rituals male deities were represented with with rounded faces and female deities with rectangular faces. The masked dancers are known as the Yei-Bi-Chi.

Yei Symbol - The Rainbow Kokopelli
A special kind of Yei deity is the Yei'bi'chai.  The Yei'bi'chai deity is revered as a "talking God" who can speak to human directly, telling them how to live in harmony with all living things.  This Yei deity also provides some simple rules of behaviour to conserve and only to use the things that were needed to survive.  Because of this advisory role this Yei spirit is known as the grandparent spirit. The "Rainbow Kokopelli" is a Yei deity who commands the rainbow, giving beauty to all those in harmony. It is thought that his sack was made of clouds full of rainbows or seeds. The "Rainbow Kokopelli" represents the Yei symbol of harmony.