from The Century Dictionary.
- noun In some heathen countries, a bush in some special locality, as near a sacred well, on which pieces of cloth are hung to propitiate the spirits supposed to dwell there. The rags are generally pieces torn from the garments of pilgrims or wayfarers.
Sorry, no etymologies found.
Heroically they forebore to growl when their legs were scraped by jagged bowlders or prickly shrubs, giving thanks inwardly to the manufacturers of their stout tweeds that their clothes held together, instead of hanging on them like streamers on a rag-bush.