whiz (n.)

"clever person," 1914, probably a special use of whiz "something remarkable" (1908), an extended sense of whizz; or perhaps a shortened and altered form of wizard. Noun phrase whiz kid is from 1930s, a take-off on a radio show's quiz kid.

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Definitions of whiz from WordNet
whiz (n.)
someone who is dazzlingly skilled in any field;
Synonyms: ace / adept / champion / sensation / maven / mavin / virtuoso / genius / hotshot / star / superstar / whizz / wizard / wiz
whiz (n.)
a buzzing or hissing sound as of something traveling rapidly through the air;
he heard the whiz of bullets near his head
whiz (v.)
make a soft swishing sound;
Synonyms: whizz / whirr / whir / birr / purr