Webster's Revised Unabridged Dictionary · 1913

Churr

Churr , noun

[Compare Chirr.]

A vibrant or whirring noise such as that made by some insects, as the cockchafer, or by some birds, as the nightjar, the partridge, etc.

Churr , intransitive verb

To make a churr, as a cockchafer.
That's the churring of the nightjar. — Hall Caine

Churr , transitive verb

To utter by churring.