The Collaborative International Dictionary of English v.0.48:

Whiz \Whiz\, v. i. [imp. & p. p. Whizzed; p. pr. & vb. n.
   Whizzing.] [Of imitative origin. ???. Cf. Whistle, and
   Hiss.]
   To make a humming or hissing sound, like an arrow or ball
   flying through the air; to fly or move swiftly with a sharp
   hissing or whistling sound. [Written also whizz.]
   [1913 Webster]

         It flew, and whizzing, cut the liquid way. --Dryden.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Whiz \Whiz\, n.
   A hissing and humming sound.
   [1913 Webster]

         Like the whiz of my crossbow.            --Coleridge.
   [1913 Webster]

WordNet (r) 3.0 (2006):

whiz
    n 1: someone who is dazzlingly skilled in any field [syn: ace,
         adept, champion, sensation, maven, mavin,
         virtuoso, genius, hotshot, star, superstar,
         whiz, whizz, wizard, wiz]
    2: a buzzing or hissing sound as of something traveling rapidly
       through the air; "he heard the whiz of bullets near his head"
    v 1: make a soft swishing sound; "the motor whirred"; "the car
         engine purred" [syn: whizz, whiz, whirr, whir,
         birr, purr]