Definition of Codex

Lat. A code or collection of laws; particularly the Code of Justinian. Also a roll or volume, and a book written on paper or parchment
—Codex Gregorianns. A collection of imperial constitutions made by Gregorius, a Roman jurist of the fifth century, about the middle of the century. It contnined the constitutions from Hadrian down to Constantine. Mao-keld. Rom. Law, § 63.
—Codex Hermogeni-anus. A collection of imperial constitutions made by Hermogenes, a jurist of the fifth cen-fury. It was nothing more than a supplement to the Codex Gregorianus, (supra,) containing the constitutions of Diocletian and Maximilian. Mackeld. Rom. Law, § 63.
—Codex Justinian-eus. A collection of imperial constitutions, made by a commission of ten persons appointed by Justinian, A. D. 528.
—Codex repetitae praelectionis. The new code of Justinian; or the new edition of the first or old code, promulgated A. D. 534, being the one now extant. Mackeld. Rom. Law, § 78. Tayl. Civil Law, 22.
—Codex Theodosianus. A code compiled by the emperor Theodosius the younger, A. D. 438, being a methodical collection, in sixteen hooks, of all the imperial constitutions then in force. It was the only body of civil law publicly received as authentic in the western part of Europe till the twelfth century, the use and authority of the Code of Justinian being during that interval confined to the Bast. 1 Bl. Comm. 81.
—Codex vetus. The old code. The first edition of the Code of Justinian ; now lost. Mackeld. Rom. Law, § 70.