Septuagint

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A Greek version of the Hebrew Scriptures that dates from the 3rd century B.C., containing both a translation of the Hebrew and additional and variant material, regarded as the standard form of Old Testament in the early Christian Church and still canonical in the Eastern Orthodox Church.

Century Dictionary and Cyclopedia

1. n. The Seventy—that is, the seventy (or more) persons who, according to the tradition, made a translation of the Hebrew Scriptures into Greek. The rounded legend is that the translation was made by seventy-two persons in seventy-two days. In another view, the Seventy were members of the sanhedrim (about seventy in number) who sanctioned the translation.
2. n. A Greek version of the Hebrew Scriptures made by the Seventy (see def. 1): usually expressed by the symbol LXX (‘the Seventy’). This version is said by Josephus to have been made in the reign and by the order of Ptolemy Philadelphus, King of Egypt, about 270 or 280 years before the birth of Christ. It is supposed, however, by modern critics that this version of the several books is the work, not only of different hands, but of separate times. It is probable that at first only the Pentateuch was translated, and the remaining books gradually; but the translation is believed to have been completed by the second century b. c. The Septuagint is written in the Hellenistic (Alexandrine) dialect, and is linguistically of great importance from its effect upon the diction of the New Testament, and as the source of a large part of the religious and theological vocabulary of the Greek fathers, and (through the Old Latin version of the Bible (see Italic) and the influence of this on the Vulgate) of that of the Latin fathers also and of all western nations to the present day. In the Greek Church the Septuagint has been in continuous use from the earliest times, although other Greek versions (see Hexapla) were anciently also in circulation, and it is the Old Testament still used in that church. The Septuagint contains the books called Apocrypha intermingled among the other books. It is the version out of which most of the citations in the New Testament from the Old are taken. Abbreviated Sept.
3. Pertaining to the Septuagint; contained in the Greek copy of the Old Testament.

Wiktionary

1. n. An ancient translation of the Hebrew Bible into Greek, undertaken by Jews resident in Alexandria for the benefit of Jews who had forgotten their Hebrew (well before the birth of Jesus); abbreviated as LXX. The LXX is the untranslated standard version of the Old Testament for the Greek Orthodox Church, but not for the Western Church, which since Jerome, has adhered to the Masoretic text. In the original Greek New Testament, when Jesus quotes the Old Testament, he is made to quote the LXX, which tends to disagree with the Masoretic text.

GNU Webster's 1913

1. n. A Greek version of the Old Testament; -- so called because it was believed to be the work of seventy (or rather of seventy-two) translators.

WordNet 3.0

1. n. the oldest Greek version of the Old Testament; said to have been translated from the Hebrew by Jewish scholars at the request of Ptolemy II