Jack Kennedy vs President Kennedy

Jack Kennedy and President Kennedy both are nouns.

Word	Noun	Adjective	Verb	Adverb
Jack Kennedy	Yes	No	No	No
President Kennedy	Yes	No	No	No

As nouns, Jack Kennedy and President Kennedy are synonyms defined as:

Jack Kennedy and President Kennedy: 35th President of the United States; established the Peace Corps; assassinated in Dallas (1917-1963)

Other synonyms of Jack Kennedy include JFK, John Fitzgerald Kennedy, Kennedy, President John F. Kennedy.

Jack Kennedy (noun)	President Kennedy (noun)
35th President of the United States; established the Peace Corps; assassinated in Dallas (1917-1963)	35th President of the United States; established the Peace Corps; assassinated in Dallas (1917-1963)