Definition from Wiktionary, the free dictionary
Unknown; perhaps from James Brumby, early Australian farrier, who is said to have left horses at his abandoned property.
brumby (plural brumbies)
- (Australia) A wild or feral horse.
- 1938, Xavier Herbert, Capricornia, Chapter VIII, p. 125, 
- I'm too weak to ride. I'd have to ride, because for one thing the white-ants have eaten the wheels of my buckboard, and my one cart-horse has gone bush with the brumbies.
1976, Tom Lee McKnight, Friendly Vermin: A Survey of Feral Livestock in Australia, page 17:
- If the latter situation prevails, brumbies can be developed into valuable stockhorses, either for use on the local property or for sale in other areas.
- Whatever the condition of a captured brumby, there is always the potential of selling it for pet food, fish bait, or even for human consumption.
1988, Tom Cole, Hell West and Crooked:
- Harry Farquharson said there were two or three springs and that the horses were “bloody wild”. He said there were probably about 300 and they were good horses, a long way above the average brumby.
- 1938, Xavier Herbert, Capricornia, Chapter VIII, p. 125,