The Collaborative International Dictionary of English v.0.48:

Antiochian \An`ti*o"chi*an\, a.
   1. Pertaining to Antiochus, a contemporary with Cicero, and
      the founder of a sect of philosophers.
      [1913 Webster]

   2. Of or pertaining to the city of Antioch, in Syria.
      [1913 Webster]

   Antiochian epoch (Chron.), a method of computing time, from
      the proclamation of liberty granted to the city of
      Antioch, about the time of the battle of Pharsalia, B.C.
      48.
      [1913 Webster]