(i.e. doctrine, from the Hebrew word "to learn") is a large collection of writings, containing a full account of the civil and religious laws of the Jews. It was a fundamental principle of the Pharisees, common to them with all orthodox modern Jews, that by the side of the written law, regarded as a summary of the principles and general laws of the Hebrew people, there was an oral law, to complete and to explain the written law. It was an article of faith that in the Pentateuch there was no precept, and no regulation, ceremonial, doctrinal or legal, of which God had not given to Moses all explanations necessary for their application, with the order to transmit them by word of mouth. The classical subject is the following in the Mishna on this wing: "Moses received the (oral) law from Sinai, and delivered it to Joshua, and Joshua to the elders, and the elders to the prophets and the prophets to the men of the Great Synagogue." This oral law, with the numerous commentaries upon it, forms the Talmud. It consists of two parts, the Mishna and Gemara.
→ The MISHNA, or "second law," which contains a compendium of the whole ritual law, was reduced to writing in its present form by Rabbi Jehuda the Holy, a Jew of great wealth and influence, who flourished in the second century of the Christian era. Viewed as a whole, the precepts in the Mishna treated men like children, formalizing and defining the minutest particulars of ritual observances. The expressions of "bondage," or "weak and beggarly elements," and of "burdens too heavy for men to bear," faithfully represent the impression produced by their multiplicity. The Mishna is very concisely written, and requires notes.
→ This circumstance led to the commentaries called GEMARA (i.e. supplement, completion), which form the second part of the Talmud, and which are very commonly meant when the word "Talmud" is used by itself. There are two Gemaras; one of Jerusalem, in which there is said to be no passage which can be proved to be later than the first half of the fourth century; and the other of Babylon, completed about 500 A.D. The latter is the more important and by far the longer.
Smith's Bible Dictionary (1884) , by William Smith.