The Collaborative International Dictionary of English v.0.48:

Churr \Churr\, v. i. [imp. & p. p. Churred; p. pr. & vb. n.
   Churr"ing.]
   To make a churr, as a cockchafer.

         That's the churring of the nightjar.     --Hall Caine.
   [Webster 1913 Suppl.]