This word has two meanings, both of which are eminently appropriate to Sri Sathya Sai Baba.
Even at the age of fourteen when Baba first declared that the world was looking for Him and that He had come to rescue it, He moved into a garden and encouraged the huge gathering of people to sing the very first Bhajan He taught. It spoke of the (Apaam) Ocean of Samsaara, very difficult to (Thara) cross; it spoke of the feet of the Guru (Baba), holding which, one can cross it.
"Maanasa Bhajare Guru Charanam, Dusthara Bhava Saagara Tharanam".
So, the announcement declared that he has come to help mankind cross the Ocean of flux (Change), of birth-growth-decline-death. His insistence on each individual discovering Him as the core of his own being is designed to save and to liberate him. See Him in you and in all; thus you merge in Him and become He.