'Theocratic' is the adjective belonging to 'theocracy': it describes a state, a government, a law or a system in which religious leaders rule and religious law is the state's law. You attach it to nouns — a theocratic state, theocratic rule, a theocratic regime, theocratic ambitions, theocratic law.

Because it is an adjective, it can also describe a direction or a flavour rather than a finished fact — 'theocratic tendencies', 'a theocratic turn' — which is how journalists use it about governments that are moving that way without having arrived. That flexibility is exactly why the adjective appears more often in the news than the noun does.

The tone follows the noun: sometimes a neutral historian's label ('the theocratic government of Geneva under Calvin'), but in modern political writing usually a warning. Its natural opposite is 'secular'. Notice the pair theocratic / theocrat: the second is the person, and it is nearly always disapproving.

Stress it on the third syllable — thee-oh-CRAT-ic — the same rhythm as democratic and bureaucratic.