A more thorough explanation:

Monopolium (mon-uh-poh-lee-uhm) is a historical term that refers to the sole power of sale, also known as a monopoly. The word comes from the Greek word monopolion, which means "a selling alone."

An example of monopolium would be if a company had complete control over the production and sale of a certain product, with no competition. This would give them the power to set prices and control the market.

Another example would be if a government granted a single company the exclusive right to provide a certain service, such as electricity or water, in a particular area. This would prevent any other companies from entering the market and competing.

These examples illustrate how monopolium can limit competition and give one entity significant power and control over a particular market or industry.