a business that has no competition

a bad thing, particularly when it came about through unfair competition," he said, referring to Microsoft's practice of distributing their web browser with their operating system

an entity which can coercively forbid its own competition

Monopoly defines a situation where a company has no competition allowing it to fix prices and usually they have policies that are intended to preserve that power and exclude competition.

A government policy to prevent freedom of competition within some area of the market.

Any successful business which is able to: (1) undercut its competitors' prices (unfair competition), (2) charge more than its competitors (price gouging), or (3) charge the same price as its competition (collusion).