adjective

of or typical of a despot; tyrannical.

a despotic regime

autocratic,dictatorial,totalitarian,authoritarian,absolute,absolutist,arbitrary,unconstitutional,undemocratic,anti-democratic,uncontrolled,unaccountable,summary,one-party,single-party,autarchic,monocratic,tyrannical,oppressive,tyrannous,repressive,harsh,ruthless,merciless,draconian,illiberal,domineering,imperious,arrogant,high-handed