Definition - What does Babaji mean?
Babaji is an Indian yogi, guru and saint. It is said that he still lives in the northern Himalayas. He is considered an avatara, a "deathless embodiment of the Divine in human form." His given name is unknown, so he is known by the name Mahavatar Babaji. This name was given to him by his disciple, Lahiri Mahasaya, who met him several times between 1861 and 1935.
Babaji was the guru who instructed Lahiri to spread the teachings of Kriya yoga. He is also reported to have appeared to Paramahansa Yogananda as he sat to pray before leaving for America in 1920. Babaji told Yogananda that he was the chosen one for spreading Kriya yoga to the West.
Yogapedia explains Babaji
In Sanskrit, mahavatar means “the great avatar," while babaji means “revered father.” Lahiri’s disciples have claimed that Babaji has legendary qualities, and is both ageless and deathless. Many consider him to be a legendary figure rather than an actual person whom many have reported meeting. There are no known records of his birth or death and little is written about his childhood.
He is known in the West primarily through the accounts of him written in Yogananda’s book, "Autobiography of a Yogi." Yogananda wrote that Jesus Christ went to India, where he met with Babaji. He envisioned Babaji’s role to be working with Christ to plan spiritual salvation for this age. He believed that Babaji and Christ were in communion, sending out vibrations to inspire nations across the world to renounce evils such as wars, racial hatreds and materialism. Yogananda was often heard praying out loud to Babaji.