my master, a title of dignity given by the Jews to their doctors of the law and their distinguished teachers. It is sometimes applied to Christ (Matt. 23:7, 8; Mark 9:5 (R.V.); John 1:38, 49; 3:2; 6:25, etc.); also to John (3:26).
a title of respect signifying master, teacher, given by the Jews to their doctors and teachers, and often addressed to our Lord. (Matthew 23:7,8; 26:25,49; Mark 9:6; 11:21; 14:45; John 1:38,49; 3:2,26; 4:31; 6:25; 9:2; 11:8) Another form of the title was Rabboni. (John 20:16) The titles were used with different degrees of honor; the lowest being rab, master then rabbi, my master ; next rabban, our master ; and greatest of all, Rabboni, my great master .
Smith's Bible Dictionary (1884) , by William Smith.