The word "Rouncy" is an archaic term that refers to a sturdy, spirited horse. In modern times, it is rarely used and has been replaced by more common synonyms such as "steed", "charger", or "mare". Other similar words that can be used in place of "rouncy" include "equine", "gelding", "pony", and "colt". Even words like "nag", "roan", or "filly" could be used in certain context to convey a sense of a lively and agile horse. Regardless of the term used, it is clear that there is something special about these majestic creatures that captures our imagination.