颼地飛;[馬達] 嗡嗡轉動
whirr n : sound of something in rapid motion; "whir of a bird's wings"; "the whir of the propellers" [syn: {whir}, {whirring}, {birr}] v 1: make a soft swishing sound; "the motor whirred"; "the car engine purred" [syn: {whizz}, {whiz}, {whir}, {birr}, {purr}] 2: make a vibrant sound, as of some birds [syn: {churr}]