The Collaborative International Dictionary of English v.0.48:
Rabbi \Rab"bi\ (r[a^]r"b[imac] or r[a^]r"b[i^]; 277), n.; pl.
Rabbis (r[a^]r"b[imac]z or r[a^]r"b[i^]z) or Rabbies.
[L., fr. Gr. "rabbi`, Heb. rab[imac] my master, from rab
master, lord, teacher, akin to Ar. rabb.]
Master; lord; teacher; -- a Jewish title of respect or honor
for a teacher or doctor of the law. "The gravest rabbies."
Be not ye called Rabbi, for one is your Master, even
Christ, and all ye are brethren. --Matt. xxiii.