professional vs athlete

professional and athlete both are nouns.

Word	Noun	Adjective	Verb	Adverb
professional	Yes	Yes	No	No
athlete	Yes	No	No	No

As nouns, athlete is a hypernym of professional; that is, athlete is a word with a broader meaning than professional:

Other hypernyms of professional include jock.

professional (noun)	athlete (noun)
a person engaged in one of the learned professions	a person trained to compete in sports
an authority qualified to teach apprentices
an athlete who plays for pay

professional (adjective)	athlete (adjective)
engaged in a profession or engaging in as a profession or means of livelihood
characteristic of or befitting a profession or one engaged in a profession
of or relating to a profession
of or relating to or suitable as a profession
engaged in by members of a profession