1. (

• whir ,
• whirr ,
• whirring ,
• birr

) sound of something in rapid motion; "whir of a bird's wings"; "the whir of the propellers" ;

1. (

• whizz ,
• whiz ,
• whirr ,
• whir ,
• birr ,
• purr

) make a soft swishing sound; "the motor whirred"; "the car engine purred" ;