Rav

Rav is the Hebrew generic term for a person who teaches Torah or is a Jewish spiritual guide or a rabbi. For example, Pirkei Avot states that:
The term rav is also Hebrew for rabbi. The term is frequently used by Orthodox Jews to refer to their own rabbi.

Overview

In the Talmud, the title Rav generally precedes the names of Babylonian Amoraim; Rabbi generally precedes the names of ordained scholars in the Land of Israel whether Tannaim or Amoraim.
In the Talmud, Rav or Rab is a common name for the amora named Abba Arikha.

The title Rav HaTzair refers to an assistant rabbi. Tzair means young, in Hebrew, and the prefix Ha means "the"; therefore, the combination can be used to mean the younger of a pair: Rav HaTzair, in context, can refer to the younger of a pair of rabbis, or Junior Rav.