noun: a manuscript volume (as opposed to a scroll), especially of an ancient text
From Latin codex (tree trunk, wood block, book).
Earliest documented use: 1581
Usage (from Wordsmith)
“The most legendary is the Voynich manuscript (a handwritten codex carbon-dated to the 15th century and thought to have originated in Central Europe), which cryptographers have still yet to solve.”
David Kushner; The Web’s Deepest Mystery; Rolling Stone (New York); Jan 29, 2015.