Webster's Revised Unabridged Dictionary · 1913

Whur

Whur , intransitive verb

[Probably of imitative origin. Compare Hurr, Hurry, Whir.]

1.
To make a rough, humming sound, like one who pronounces the letter r with too much force; to whir; to birr.
2.
To snarl or growl, as a dog. — Halliwell

Whur , noun

A humming or whirring sound, like that of a body moving through the air with velocity; a whir.