whirr

verb

1. To move or vibrate (something) with a buzzing sound.
2. (intransitive)To make a sibilant buzzing or droning sound.

   “In a city where media companies and hospitals have armed guards, this accessibility is unusual. Inside, drivers sit and chat in between shifts, the overhead fan whirring and causing the dim electric light to flicker over their faces.”

3. (transitive)To cause (something) to make such a sound.
4. (intransitive)(of a panther) To make a vibrating sound in its throat when contented, much like the domestic cat’s purr.

noun

1. A sibilant buzz or vibration; the sound of something in rapid motion.

   “At that moment a flight of birds passed close overhead, and at the whirr of their wings a panic fear seized her.”

   “Then the exploding whirr of wings in the wind — a mixed covey of bobwhites and scalies.”

2. A bustle of noise and excitement.
3. The vibrating sound made by a panther in its throat when contented.