The Collaborative International Dictionary of English v.0.48:

Autarchy \Au"tar*chy\, n. [Gr. ? independence; a'yto`s self +
   'arkei^n to be sufficient.]
   1. Self-sufficiency, especially economic self-sufficiency as
      applied to nations. [Obs.] --Milton.
      [1913 Webster +PJC]

   2. same as autarky.

   Syn: autarky.
        [WordNet 1.5] autarkic

WordNet (r) 3.0 (2006):

autarchy
    n 1: economic independence as a national policy [syn: autarky,
         autarchy]
    2: a political system governed by a single individual [syn:
       autocracy, autarchy]