whirr

n : sound of something in rapid motion: "whir of a bird's

wings"; "the whir of the propellers" [syn: {whir}, {whirring}]

v 1: make a soft swishing sound, as of a motor working or wings

flapping [syn: {whizz}, {whiz}, {whir}, {birr}, {purr}]

2: make a vibrant sound, as of some birds [syn: {churr}]