whiz vs expert

whiz and expert both are nouns.

Word	Noun	Adjective	Verb	Adverb
whiz	Yes	No	Yes	No
expert	Yes	Yes	No	No

As nouns, expert is a hypernym of whiz; that is, expert is a word with a broader meaning than whiz:

whiz (noun)	expert (noun)
a buzzing or hissing sound as of something traveling rapidly through the air	a person with special knowledge or ability who performs skillfully
someone who is dazzlingly skilled in any field

whiz (adjective)	expert (adjective)
	having or showing knowledge and skill and aptitude
	of or relating to or requiring special knowledge to be understood

whiz (verb)	expert (verb)
make a soft swishing sound