sovereign vs chief of state

sovereign and chief of state both are nouns.

Word	Noun	Adjective	Verb	Adverb
sovereign	Yes	Yes	No	No
chief of state	Yes	No	No	No

As nouns, chief of state is a hypernym of sovereign; that is, chief of state is a word with a broader meaning than sovereign:

sovereign: a nation's ruler or head of state usually by hereditary right
chief of state: the chief public representative of a country who may also be the head of government

Other hypernyms of sovereign include head of state, ruler, swayer.

sovereign (noun)	chief of state (noun)
a nation's ruler or head of state usually by hereditary right	the chief public representative of a country who may also be the head of government

sovereign (adjective)	chief of state (adjective)
greatest in status or authority or power
(of political bodies) not controlled by outside forces