Answer:

WHIR

Answer	Crossword Clue
WHIR	Fan noise
WHIR	Humming sound
WHIR	Make a hum

WHIR	Run like an engine
WHIR	Noise from the fans?
WHIR	Propeller sound
WHIR	Spin and hum
WHIR	Engine sound
WHIR	Going-around sound
WHIR	Machinery sound
WHIR	Fan sound

WHIR	Spinning sound
WHIR	Blender sound
WHIR	Propeller noise
WHIR	Sound from a fan
WHIR	Helicopter motion
WHIR	Revolve, as a fan
WHIR	Fan's noise
WHIR	Sound of a small fan

WHIR	Mixer noise
WHIR	Sound of spinning blades
WHIR	The sound of a fan
WHIR	Revolutionary sound?
WHIR	Vibratory sound
WHIR	Sound like a fan
WHIR	Helicopter sound
WHIR	Rotor noise

WHIR	Fan's sound
WHIR	Buzzing sound
WHIR	Spin like a top
WHIR	Sound of a fan
WHIR	Electric-fan sound
WHIR	Moving-around sound
WHIR	Sound from a propeller
WHIR	Electric fan sound

WHIR	Commotion.
WHIR	Buzzing sound.
WHIR	Buzzing.
WHIR	Sound of a fan.
WHIR	Sound of flight.

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.