4 occurrences in 4 dictionaries
Reference: Rabboni
Easton
(id.) occurs only twice in the New Testament (Mr 10:51, A.V., "Lord," R.V., "Rabboni;" Joh 20:16). It was the most honourable of all the titles.
Hastings
Morish
Rabbo'ni
Lit. 'My master, or teacher.' Mr 10:51 (translated 'Lord' in A.V.); Joh 20:16. See RABBI.
Smith
Rabbo'ni.
Joh 21:25
[RABBI]
See Rabbi