potentate vs autocrat

potentate and autocrat both are nouns.

Word	Noun	Adjective	Verb	Adverb
potentate	Yes	No	No	No
autocrat	Yes	No	No	No

As nouns, autocrat is a hyponym of potentate; that is, autocrat is a word with a more specific, narrower meaning than potentate:

Other hyponyms of potentate include shogun, strongman, despot, tyrant.

potentate (noun)	autocrat (noun)
a ruler who is unconstrained by law	a cruel and oppressive dictator