The wordrabbi, which means a religious "teacher", is commonly used in English to refer to any ordained Jewish scholar. Literally, Rabbi means "my master". It is the same Hebrew word as Rav, with the possessive suffixi. Although it is technically a possessive form, it is used as a general title even for those who are not one's personal teacher, particularly for the Tannaim, and, in its English form, for any rabbi. In Israel, among the Haredim, Rabbi can be used colloquially interchangeably with the Yiddish Reb, and is used as a friendly title, similar to calling someone "Sir".
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 personalspiritual guide, similar to Rabbi. In Modern Hebrew, Rav is used for all rabbis, equivalent to the English "Rabbi." It 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 a craft or art. 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 whom the speaker usually consults. In some communities, "Rav" is also used like "Reb". This is common in Judeo-Czech.
Rebbe
may refer to the leader of a Hasidic Judaism movement, a person's main rosh yeshiva or mentor, or to an elementary school teacher as referred to by his/her students. In many Hasidic groups the Rebbe gives spiritual guidance; but for questions of halakhah they ask a Rav. This Rav is sometimes referred to as the Rav of the Hasidic group. This position normally is occupied by the Av Beis Din or chief justice, of a Hasidic group. In some Hasidic groups, such as Belz and Satmar, the Rebbe and Rav are concurrent positions. In Hasidic groups with similar organizations, the Admo"r will be referred to by the interchangeable titles. In those groups where the positions are divided, they will not. For example, the Satmar Rav and the Satmar Rebbe are the same person. The Breslover Rebbe and the Breslover Rav are not.
Other honorifics
Other honorifics include Admo"r, K'vod K'dushas, Shlit"a and Shy'.
Moreh / Morah
Hebrew honorific for a teacher, professor, or learned sage. In Hebrew, Moreh is masculine, Morah is feminine. However, a rabbi may also be called Morah d'Asra, which is Aramaic for "leader of the place."
Admo"r
"Admor" is an acronym for "Adonainu, Morainu, VeRabbeinu," a phrase meaning "Our Master, Our Teacher, and Our Rabbi." This is an honorific title given to scholarly leaders of a Jewish community. In writing, this title is placed before the name, as in "Admor of Pinsk" or “R' Ploni Almoni, Admor of Redomsk.”
Gadol Hador
This term is used to point to a leader of the generation, for example Rav Aharon Yehuda Leib Shteinman was considered one until his death in 2017.
Hakham
"Hakham" is an alternate title for rabbis but also includes some sages. It is also the primary title of Karaite spiritual leaders, perhaps on the Sephardic model but also to emphasize their role as advisors rather than authorities.
K'vod K'dushat
"K'vod K'dushat," meaning “The honor of holiness”. This title is usually placed before the name. It is found as early as in the 1531 edition of the Arukh.
Maskil
The word "Maskil" or "ha-maskil" indicates a scholar or an "enlightened man", used before the name. It was also used for activists in the Haskalah movement of the 18th and 19th centuries.
Qess
The Beta Israel community of Ethiopia refers to its spiritual leaders as Qessoch ቄሶች, sometimes translated as "pastors" or "sages." A single sage would be a Qess ቄስ. Qessoch are also known as kahənat ካሀንት, which literally translates to "priests." Unlike the Hebrew kohen, an Ethiopian kahən is not necessarily of Aaronide descent.
Shlit"a
'Shlit"a' is an acronym for "Sheyikhye Le'orech Yamim Tovim Amen," “May he live a good long life, Amen,” given to a revered rabbi or to someone's child's Rebbe. This title is usually placed after the name and/or other title. Examples:
Note that the Rebbe sh'lita has instructed and requested all of Bar Mitzvah age and older not to chat when wearing tefillin.
HaGaon HaRav Shmuel Yaakov Borenstein, Shlita, To Address Acheinu Parlor Meeting In Flatbush.
Shy'
"Shy'" is an acronym for "Sheyikhye," meaning “May he live”. This title is usually placed after the name.
In reference to levite descent. Used preceding surname. When calling a man to read the Levite portion of the Torah service, he is called by his given name-in-Israel, followed by his patronymic, followed by "haLevi"., whose father's given name is/was Abraham.
HaCohen
In reference to Priestly descent. Used preceding surname.