Enter a clue or pattern or both:
The ClueChopper sound (4 letter answer)
NotesThe answer WHIR is seen occasionally, appearing about once every 750 puzzles.
Result of a quick revolution
Revolve with a humming sound
DefinitionWHIR as a noun:
1. (whir, whirr, whirring, birr) = sound of something in rapid motion; "whir of a bird's wings"; "the whir of the propellers"
WHIR as a verb:
1. (whizz, whiz, whirr, whir, birr, purr) = make a soft swishing sound; "the motor whirred"; "the car engine purred"