definition of
whirr

[1] #1 whirr n. [whir, whirring, birr] sound of something in rapid motion; "whir of a bird's wings"; "the whir of the propellers". wn

[2] #2 whirr v. [whizz, whiz, whir, birr, purr] make a soft swishing sound; "the motor whirred"; "the car engine purred". wn

[3] #3 whirr v. [churr] make a vibrant sound, as of some birds. wn