WordNet (r) 3.0 (2006):

self-governing
    adj 1: (of political bodies) not controlled by outside forces;
           "an autonomous judiciary"; "a sovereign state" [syn:
           autonomous, independent, self-governing,
           sovereign]

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "self-governing":
   absolute, aristocratic, autarchic, autarkic, authoritarian,
   autocratic, automated, automatic, automatous, autonomous,
   bureaucratic, civic, civil, constitutional, cybernated, democratic,
   despotic, dictatorial, fascist, federal, federalist, federalistic,
   free-spirited, freewheeling, governmental, gubernatorial,
   heteronomous, independent, individualistic, inner-directed,
   matriarchal, matriarchic, monarchal, monarchial, monarchic,
   monocratic, neutral, nonaligned, nonpartisan, official, oligarchal,
   oligarchic, parliamentarian, parliamentary, patriarchal,
   patriarchic, pluralistic, political, popular, republican,
   self-acting, self-active, self-adjusting, self-closing,
   self-contained, self-controlled, self-cooking, self-dependent,
   self-determined, self-directed, self-directing, self-dumping,
   self-governed, self-lighting, self-operative, self-regulative,
   self-reliant, self-starting, self-subsistent, self-sufficient,
   self-supporting, self-winding, self-working, semiautomatic,
   sovereign, spontaneous, theocratic, third-force, third-world,
   totalitarian