In the Jewish world of the Diaspora (and also in Palestine), historical and linguistic conditions had, as early as the third century b.c.e., led to the translation of the Bible into Greek. Similar reasons explain the origin of Targums. The problems posed in this connection, however, are considerably greater and more complex than for the LXX.
The word targum signifies ‘translation’ and derives from the verb tirgem meaning ‘to translate’, ‘to explain’, or ‘to read out’ (compare Ezra 4:7); it is a denominative of turgeman (= interpreter) to which an Akkadian origin is generally attributed. In rabbinic usage tirgem is employed to designate a version translated from the Hebrew into any language whatever (y. Kidd i.59a;y. Meg. 1.71c), but targum is used only for a translation of the Bible into Aramaic or for the Aramaic passages of the Old Testament (Yad. 4.5). The professional Synagogue translator was called turgeman or meturgeman (Meg. 4.4). As a literary genre Targum is distinct from Midrash in that it is primarily a translation and not a commentary and, in its strictest definition, a translation intended for the liturgy of the Synagogue.
We now possess Targums of all the books of the Bible, with the exception of Ezra-Nehemiah and Daniel. Until recently the most commonly accepted opinion was that these were late productions, distributed between the fourth and fifth centuries c.e. and the Middle Ages. It was conceded that the institution of Targum itself was pre-Christian; but because of the prohibition upon putting into writing the oral tradition, the texts themselves could not have been anterior to the first writings of rabbinic Judaism (about 200 c.e.).