From BiblePortal Wikipedia

Holman Bible Dictionary [1]

The word comes directly from the Latin meaning “tree trunk,” possibly describing a stack of wooden tablets, each coated with wax on one side for writing and held together by leather thongs inserted in holes bored along one side. For centuries papyrus and parchment made from animal skins were popular writing materials because they could be shaped into long strips and rolled into a scroll. Using the scroll required both hands, however, and someone decided to cut a scroll into equal-sized sheets, stack them in order, and stitch them together along one edge. So, the scroll became a codex.

Biblical manuscripts produced in the codex form were all handcopied in Greek capital letters on parchment from older manuscripts. Nearly 250 of these manuscripts in codex form are now preserved in various libraries and museums. They have been dated from the fourth to the eleventh centuries. The oldest and most complete is Codex Sinaiticus now in the British Museum. It contains about 350 sheets that measure 15 by 13 1/2 inches with four columns of lettering per page. It was discovered accidentally in 1844 by a Russian scholar in a monastery at the foot of Mount Sinai. It contains all the New Testament and most of the Old. Another important codex from the fourth century is in the Vatican Library in Rome. A fifth-century manuscript of the four Gospels is known as Codex Washingtonianus and is housed in the Freer Gallery of Art in Washington, D. C.

William J. Fallis

Webster's Dictionary [2]

(1): (n.) An ancient manuscript of the Sacred Scriptures, or any part of them, particularly the New Testament.

(2): (n.) A collection or digest of laws; a code.

(3): (n.) A book; a manuscript.

(4): (n.) A collection of canons.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [3]

For the important Biblical MSS., see each under its specific name; as (See Amiatine); (See Angelic); (See Arienteus), etc.