The term 'superstate' is used to describe a large, powerful state that has control over many other states. The crossword solution for the term 'superstate' is 'Eurasia, ' which is a supercontinent composed of Europe and Asia. Eurasia is the largest landmass on Earth, covering over 10 million square miles. It is home to over 4 billion people, making it one of the most populous regions in the world. Eurasia is also home to some of the world's most powerful countries, such as Russia, China, and India.