An official rabbi who renders legal decisions. Many of the Rebbes were both a Rebbe of Chasidim, and the Rov of the city inwhich they lived.
Rabbi, religious leader of the community
Sage; Teacher Also a Sage of the Talmudic era who lived in Babylonia and composed today's form of the Aleinu prayer
(pl. Rabbonim): rabbi or, literally, "teacher."
pl. Rabbanim: Rabbi, Torah teacher.
Rav (Heb. רב) is the Hebrew word for rabbi. For a more nuanced discussion see semicha. In Talmudic literature this word could also refer to a master of a slave.