John 20:16 "Jesus said to her, "Mary!" She turned and said to Him, "Rabboni!" (which is to say, Teacher)."
"She turned and said to Him, Rabboni"
A common title of distinction during the time of Jesus was the term "Rabbi." In Hebrew it was "Ravi," pronounced (Rahbee). The Greek was "Hrabbi" and they both mean the same thing "My Master" or "My Teacher."
It was actually a new term that had developed sometime either during or after the schism which arose between the schools of Hillel and Shammai. Actually the first person we know of in history to have been honoroed with this title was Gamaliel I sometime around 30 AD. The title that Jesus had rebuked so often was actually very popular and very new.
There were actually three forms of the title, each given with elaborate ceremony:
"Rab" meaning "Master" was apparently, according to early Babylonian works, a Babylonian title given to certain learned men who had received the laying-on of hands in the rabbinic schools. This was the lowest title among the three.
"Rabbi" meaning "My Master" was a Palestinian designation, where a man was bestowed the title from the laying-on of hands by the Sanhedrin. The ceremony was interesting. The man was placed on a "high" chair which was raised above the assembly and he was given a key and a scroll when the new title was spoken by a certain person. The key symbolized power and authority to teach others, and the scroll symbolized that he was familiar and devoted to his studies. He would wear the key as a token of greatness and it was buried with him. According to the Aruch (Talmudical lexicon) a "Rabbi" was one who has disciples, and whose disciples were prepared to raise up new disciples. This was the second greatest title among the three.
"Rabbon" which meant "Great Master" or "Rabboni" meaning "My Great Master" was the greatest designation of all. It is properly pronounced (Rahbonee). Once the teacher had seen two generations of disciples he was referred to with this title, and also called by his own name so that he would not be forgotten.
It is interesting to note that men who had earned these titles were very highly respected, and Jesus was called by both.
Mary, a woman who had been scorned much of her life, by both men and women, and even somewhat by the disciples, was received by Jesus and raised to a place of special greatness, to the extent that it was she, a woman, who had been the first to behold Jesus after His resurrection, and speak the word "Rabboni" in a ceremony that was unseen by men, as He was raised from death, above the assembly.
Bibliography on Ancient Customs
The Art of Ancient Egypt, Revised by Robins, 272 Pages, Pub. 2008