not satisfied or content with currently prevailing conditions or circumstances.

dissatisfied with the existing government, administration, system, etc.

a malcontent person, esp. one who is chronically discontented or dissatisfied.

adjective

belly-aching , complaining , discontented , disgruntled , unhappy , unsatisfied , agitator , anarchist , complainer , dissatisfied , grouch , grouchy , grumbler , insurgent , rebel , rebellious , revolter , troublemaker , uneasy