Rav
"Rav" is the Hebrew word for "master," and is closely related to the Hebrew form which gives rise to the English "Rabbi." "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, equivalent to the English "Rabbi."
In the Orthodox non-Hebrew speaking world, "Rabbi" is often used as a lesser title, with more famous rabbis receiving the title "Rav".
When used alone, "the Rav" refers to the posek (Jewish legal decisor) whom the speaker usually consults.
In some communities, "Rav" is also used like "Reb". This is common in Judeo-Czech.
Read more about this topic: Honorifics In Judaism