Rabboni
Easton's Dictionary
(id.) occurs only twice in the New Testament (Mark 10:51, A.V., “Lord,” R.V., “Rabboni;” John 20:16). It was the most honourable of all the titles.
International Standard Bible Encyclopedia
rab-o'-ni, rab-o'-ni (rhabboni, "my great master" (Mr 10:51); rhabbouni (Westcott-Hort rhabbounei), (Joh 20:16)).of agoraios (literally, "lounger in the market place"), in Ac 17:5, where it replaces "baser sort" of the King James Version. It has the common meaning of an unruly, lawless set who are ready to join a mob.
See RABBI.