whirring
    adj 1: like the sound of rapidly vibrating wings
    n 1: sound of something in rapid motion; "whir of a bird's
         wings"; "the whir of the propellers" [syn: whir, whirr,
         whirring, birr]

Whir \Whir\, v. i. [imp. & p. p. Whirred; p. pr. & vb. n.
   Whirring.] [Perhaps of imitative origin; cf. D. hvirre to
   whirl, and E. hurr, hurry, whirl. ???.]
   To whirl round, or revolve, with a whizzing noise; to fly or
   more quickly with a buzzing or whizzing sound; to whiz.
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         The partridge bursts away on whirring wings. --Beattie.
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