The word means “my teacher,” and in the New Testament era it was a title of respect to teachers of the Jewish law. Several people used it when addressing Jesus—most memorably Judas Iscariot at the time of betrayal: Judas said, “‘Greetings, Rabbi!’ and kissed Him” (Matt. 26:49).
Jesus criticized the Pharisees for putting on religious airs; they loved to be greeted in the marketplaces and to have men call them “Rabbi.” “But you, do not be called ‘Rabbi’; for One is your Teacher, the Christ, and you are all brethren” (Matt. 23:8).