Chief Executive vs United States President

Chief Executive and United States President both are nouns.

Word	Noun	Adjective	Verb	Adverb
Chief Executive	Yes	No	No	No
United States President	Yes	No	No	No

As nouns, Chief Executive and United States President are synonyms defined as:

Chief Executive and United States President: the person who holds the office of head of state of the United States government

Other synonyms of Chief Executive include President, President of the United States.

Chief Executive (noun)	United States President (noun)
the office of the United States head of state	the person who holds the office of head of state of the United States government
the person who holds the office of head of state of the United States government