* A made-up name: Someone might have created it for personal use, such as for a business, a fictional character, or an online alias.
* A specific context: Perhaps you heard it in a particular movie, book, or game. If you can provide more context, I may be able to help decipher its meaning.
* A misheard word: It's possible you misheard another word that sounds similar. Do you remember anything else about the situation where you encountered "Queenstar"?
Without more information, it's impossible to determine the exact meaning of "Queenstar."