https://en.wikipedia.org/wiki/Honorifics_in_Judaism
"Rav" is the Hebrew word for "master.""Rav" can be used as a generic honorific for a teacher or a personal spiritual guide, similar to Rabbi. In Modern Hebrew, Rav is used for all rabbis. The word can also be used as a prefix to a profession or title to show high rank or profficiency. For example: רב חובל, rav-sailor, meaning ship captain, or רב אומן, rav-artist, meaning master of ...