The Collaborative International Dictionary of English v.0.48:

Autonomy \Au*ton"o*my\, n. [Gr. ?: cf. F. autonomie. See
   Autonomous.]
   1. The power or right of self-government; self-government, or
      political independence, of a city or a state.
      [1913 Webster]

   2. (Metaph.) The sovereignty of reason in the sphere of
      morals; or man's power, as possessed of reason, to give
      law to himself. In this, according to Kant, consist the
      true nature and only possible proof of liberty. --Fleming.
      [1913 Webster]

WordNet (r) 3.0 (2006):

autonomy
    n 1: immunity from arbitrary exercise of authority: political
         independence [syn: autonomy, liberty]
    2: personal independence [syn: autonomy, self-direction,
       self-reliance, self-sufficiency]

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "autonomy":
   Declaration of Independence, absolute monarchy, aristocracy,
   autarchy, autarky, autocracy, autonomousness, coalition government,
   colonialism, commonwealth, constitutional government,
   constitutional monarchy, democracy, dictatorship, dominion rule,
   duarchy, duumvirate, dyarchy, federal government, federation,
   feudal system, free will, garrison state, gerontocracy,
   gratuitousness, heteronomy, hierarchy, hierocracy, home rule,
   independence, individualism, inner-direction, limited monarchy,
   martial law, meritocracy, militarism, military government,
   mob rule, mobocracy, monarchy, neocolonialism, ochlocracy,
   oligarchy, pantisocracy, patriarchate, patriarchy, police state,
   pure democracy, regency, representative democracy,
   representative government, republic, rugged individualism,
   self-action, self-activity, self-containment, self-determination,
   self-direction, self-government, self-reliance, self-sufficiency,
   social democracy, spontaneity, spontaneousness, stratocracy,
   technocracy, thearchy, theocracy, totalitarian government,
   totalitarian regime, triarchy, triumvirate, tyranny, unforcedness,
   voluntariness, voluntarism, voluntaryism, volunteer, volunteering,
   welfare state