If you're talking about a royal title:
* King: The male counterpart of a queen.
* Emperor/Empress: A monarch ruling over an empire.
If you're talking about a chess piece:
* King: The most important piece in chess, which is protected by the queen.
If you're talking about a woman in a figurative sense (e.g., "the queen of the kitchen"):
* No single word: The opposite would depend on the specific context. For example, you might say "the king of the kitchen" if it's a man who's a great cook, or use a phrase like "the least skilled cook in the family."
It's important to consider the context to find the most appropriate opposite.