If Rabbi is used as an honorific (like Mr. or Dr.) in an context where it would be obvious that such a person is a rabbi, such as a transcript of the Talmud, Rabbi can be abbreviated as R. (in English) or .ר (in Hebrew). However, this only works in a clear context and most often the word "Rabbi" is unabbreviated.
In English, I have seen Rav. as an abbreviation, but it is not common. Most often Rabbi is used in full.
In Hebrew, there is R. ('ר) which is the abbreviation for Rabbi.
Originally, it was a rabbi, a rabbi, and a rabbi walk into a bar. . .
Rabbis. Here are a few examples from the Talmud. Rabbi Yochanan ben Zakkai, Rabbi Yonatan ben Uziel, Chanina ben Dosa, Bava ben Buta, Shimon ben Hillel, Rabbi Eliezer, Rabbi Yehoshua, Rabbi Yossi haKohen, Rabbi Shimon ben Netanel, Rabbi Elazar ben Arakh, Rabbi Yochanan ben Nuri, Rabbi Akiva, Rabbi Nechuniah, Rabbi Nachum Gamzu, Rabbi Yossi Glili, Rabbi Honi Me'agel, Rabbi Abba Shaul, and hundreds of others. Each of these had large groups of disciples.
Rabbi Aaron Teitelbaum and Rabbi Zalman Leib Teitelbaum
The rabbi of France
A rabbi is a teacher.
A Chief Rabbi
Rabb Rabbi The Rabbi also Engineer Rabbi
Rabbi Yochanan ben Zakkai, Rabbi Yonatan ben Uziel, Chanina ben Dosa, Bava ben Buta, Shimon ben Hillel, Rabbi Eliezer, Rabbi Yehoshua, Rabbi Yossi haKohen, Rabbi Shimon ben Netanel, Rabbi Elazar ben Arakh, Rabbi Yochanan ben Nuri, Rabbi Akiva, Rabbi Nechuniah, Rabbi Nachum Gamzu, Rabbi Yossi Glili, Rabbi Honi Me'agel, Rabbi Abba Shaul, and hundreds of others. Each of these had large groups of disciples.
The Rabbi visited the factory in order to ascertain its fitness for Kashrut (Kosher) certification.
A Rabbi is very significant.
The rabbi's private office
Rabbi Benzion Halberstam son of Rabbi Shlomo Halberstam (2)