Designating or relating to the code of laws originating with Justinian (483–565), Byzantine emperor 527–565, or the laws that comprise it.
The compilation of Roman laws known as the "Justinianian code" was made by order of Justinian, and published in 529, then in a revised form in 534. The term may also embrace all the compilations of Roman law made by Justinian's command, including the pandectae, institutiones, and novellae: see "pandect", "Institutes of Justinian", "novel".
Early 18th century; earliest use found in Thomas Baker. Partly from post-classical Latin Justinianeus of or belonging to Justinian + -an;.