whirr BrE AmE , whir /wɜː $ wɜːr/ verb ( past tense and past participle whirred , present participle whirring ) [intransitive]
[ Date: 1300-1400 ; Origin: Probably from a Scandinavian language ]
to make a fairly quiet regular sound, like the sound of a bird or insect moving its wings very fast:
Helicopters whirred overhead.
—whirr noun [countable usually singular] :
the whirr of an electric motor