I can help there. A Brumby is a wild/feral horse. Sometimes the term Brumby is used to specifically describe a domesticated horse that has been turned loose to fend for itself and not been recaptured for some time, thereby not improving its temperament and increasing the time it takes to 'break in' again.

It can also (whilst drinking alcohol) be used to refer to a female member of the human species. Usually the description improves with the quantity of alcohol consumed.

You did ask.....