Definition of Justinianian in US English:

Justinianian

(also Justinianean)

adjective

Roman Law
  • Designating or relating to the code of laws originating with Justinian (483–565), Byzantine emperor 527–565, or the laws that comprise it.

Origin

Early 18th century; earliest use found in Thomas Baker. Partly from post-classical Latin Justinianeus of or belonging to Justinian + -an;.