Excellency vs important person

Excellency and important person both are nouns.

Word	Noun	Adjective	Verb	Adverb
Excellency	Yes	No	No	No
important person	Yes	No	No	No

As nouns, important person is a hypernym of Excellency; that is, important person is a word with a broader meaning than Excellency:

Excellency: a title used to address dignitaries (such as ambassadors or governors); usually preceded by `Your' or `His' or `Her'
important person: a person whose actions and opinions strongly influence the course of events

Other hypernyms of Excellency include influential person, personage.

Excellency (noun)	important person (noun)
a title used to address dignitaries (such as ambassadors or governors); usually preceded by `Your' or `His' or `Her'	a person whose actions and opinions strongly influence the course of events