Byzantine

adjective

• 1relating to Byzantium, the Byzantine Empire, or the Eastern Orthodox Church.
• of an ornate artistic and architectural style which developed in the Byzantine Empire and spread to Italy, Russia, and elsewhere. The art is typified by religious wall paintings and icons and the architecture by many-domed churches.

• 2 (also byzantine) (of a system or situation) excessively complicated, and typically involving a great deal of administrative detail:Byzantine insurance regulations
• characterized by deviousness or underhand procedure:he has the most Byzantine mind in politics

noun

• a citizen of Byzantium or the Byzantine Empire.