A very common way of referring to the Buddha in many Buddhist sutras.
Yet another thing Christians have borrowed from Buddhism. No, just kidding on this one. Actually, English translators no doubt borrowed the term from them. It is not a very good translation of Bhagavan - the generous one, but it can be seen in many English translations anyway.
Though Christians did borrow from Buddhism: e.g., the Catholic rosary, or the story of the wise men (often misinterpreted as "Three Kings"), and of course both the Buddha and Jesus said "Eat what's put into your bowl."
Bhagavan - generous has no socio-political implications. After his awakening the Buddha was at first hesitant about teaching others but then decided to do so anyway. His generosity is his willingness to share his understanding with others.