from The Century Dictionary and Cyclopedia
- n. A disease in horses in which a ball is sometimes formed in the intestinal canal, owing to over-feeding with the dust of corn or barley.
Sorry, no etymologies found.
Before any other alarm had struck her brain, the hand she felt with was in a palsy, her mouth gaped, her throat thickened, the dust-ball rose in her throat, and the effort to swallow it down and get breath kept her from acute speculation while she felt again, pinched, plucked at the thing, ready to laugh, ready to shriek.
I suspect it was a pilot becoming disoriented in a dust-ball on take-off - although that's just a wild-assed guess on my part.