* Prosperous: This means successful or thriving, usually in terms of wealth or fortune.
* Anos: This means "years" in Spanish.
* Amigo: This means "friend" in Spanish.
If you put these words together, "prosperous anos amigo" could be interpreted as "prosperous years, friend" or "have prosperous years, friend".
It's possible that the phrase was created as a well-wishing statement, similar to saying "Happy New Year" or "Wishing you all the best". However, it's not a common or standard phrase in Spanish.
If you have more context, please provide it so I can give you a more accurate interpretation.