Before we start, a quick distinction: something is only a monopoly if it single-handedly controls an entire industry. If it shares that power with a few other countries, as many corporations do today, it's an oligopoly, where the influence is held by and the terms are dictated by a few rich companies. All right, into the etymology: the word monopoly came to us in the early sixteenth century from the Romans, whose word monopolium came from the Greeks. Here we can separate the word into its components: monos, meaning "single", and polein, meaning "to sell". This alludes to how a monopoly is a specific person or business is the single one to have selling rights for a particular product. Monos comes from the Proto-Indo-European root men, meaning "isolated", polein comes from the PIE root pel, also meaning "to sell", and that's the whole story.
Adam Aleksic, a leading contender for valedictorian of his high school, is a 215-month-old boy with disturbing interests in etymology, vexillology, geography, and law. Adam would like to one day visit Tajikistan and probably isn't spying for the Uzbek government.
The Etymology Nerd