Synonyms for Rebellious (same or very similar meaning)
WordNet sense 1 (deserting your allegiance or duty to leader or cause or principle):
disloyalWordNet sense 2 (discontented as toward authority):
disaffected, malcontent, ill-affectedWordNet sense 3 (showing or experiencing dissatisfaction or restless longing):
discontent, discontentedFrom the ODE community, based on WordNetadd/edit