Definition of "caballing"

And lastly, the examinant saith, that from the beginning of these conversations with the said Mary Burton, about these plottings and caballings between the Hughsons and the negroes […]

1810, Daniel Horsmanden, The New York Conspiracy

In all these negotiations, and caballings, and intriguings, the person most concerned, Frances Coke, the beauty and the heiress, was only the ball in the game.

1909, Thomas Longueville, The Curious Case of Lady Purbeck