The Tetragrammaton, referred to in rabbinic literature as HaShem (The Name) or Shem Hameforash (The Special Name), is the word used to refer to the four-letter word, yud-hey-vav-hey (יהוה), that is the name for God used in the Hebrew Bible.
The name, which some people pronounce as Yahweh and others (mostly Christians) as Jehovah, appears 5,410 times in the Bible (1,419 of those in the Torah).
It is unclear what the original pronunciation of the word was, due to the longstanding Jewish prohibition on speaking God’s name aloud. Instead, a variety of pseudonyms are used, such as Adonai (Lord), Elohim (God) and HaShem (The Name).
The four letters of the Tetragrammaton form the root meaning “to be,” and some have understood the original meaning to be “He-Who-Is,” or “He who brings being into being.”
The origin of the taboo on pronouncing God’s name aloud — viewing this as irreverent or possibly even a violation of the commandment not to take God’s name in vain — is not entirely clear. However, some attribute it to a Temple practice in which only the High Priest was allowed to utter the name, and only when in the Temple and reciting the priestly blessing. In the Mishnah (in Sanhedrin 10:1), as Rabbi Louis Jacobs notes in The Jewish Religion, the sage Abba Saul declares that one who pronounces the divine name with its letters (i.e. as it is spelled) has no share in the World to Come.
Some Jews and non-Jews have suggested that the name itself has magical power, an idea that Maimonides dismissed but that is embraced in some Kabbalistic (Jewish mystical) texts.
Adapted in part from the Jewish Encyclopedia.
Pronounced: ah-doe-NYE, Origin: Hebrew, a name for God.
Pronounced: kah-bah-LAH, sometimes kuh-BAHL-uh, Origin: Hebrew, Jewish mysticism.
Pronounced: MISH-nuh, Origin: Hebrew, code of Jewish law compiled in the first centuries of the Common Era. Together with the Gemara, it makes up the Talmud.
Pronounced: hah-SHEMM, Origin: Hebrew, literally, “the name,” word used to refer to God.