autocrat vs tyrant

autocrat and tyrant both are nouns.

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

As nouns, autocrat and tyrant are synonyms defined as:

Other synonyms of autocrat include despot.

autocrat (noun)	tyrant (noun)
a cruel and oppressive dictator	a cruel and oppressive dictator
	any person who exercises power in a cruel way
	in ancient Greece, a ruler who had seized power without legal right to it