A Sanskrit term meaning literally a being of bodhi (or enlightenment), a being destined for enlightenment, or one whose energy and power is directed toward enlightenment. A bodhisattva is one who is destined to become a Buddha but has foregone the bliss of nirvana with a vow to save all children of God on earth.
In the Mahayana school of Buddhism, becoming a bodhisattva is the goal of the Path. The path of the bodhisattva is generally divided into ten stages, called bhumis. The bodhisattva strives to progress from one stage to the next until he obtains enlightenment.
For more information
Elizabeth Clare Prophet, Maitreya on Initiation
Mark L. Prophet and Elizabeth Clare Prophet, Saint Germain On Alchemy: Formulas for Self-Transformation.