Rabboni is a form of Rabbi. In Jesus' day it was a term of dignity given by the Jews to their distinguished teachers. The Pharisees loved to be called 'Rabbi'; but Jesus told his disciples, " Do not be called 'Rabbi'; for One is your teacher, the Christ, and you are all brethen" ( Matt, 23:7-8).
In our day rabbi means a Jew trained for professional religious leadership. The ordained spiritual leader of a jewish congregation, the rabbi is an official formally authorized to interpret Jewish law.
The word rabbi comes from a semitic root word meaning "great" or "head". It is only used in the gospels, usually of Jesus. The disciples of John the Baptist also addressed him as rabbi (John 3:26).
Your definition of a teacher will be added to an essay for school titled Ideal Teacher. A teacher has many faces but one body. thanks and God Bless