The word police was first used around the year 1440 by author Stephen Scrope in a translation of a French book by Christine de Pizan, The Epistle of Othea. In it, a knight is described as policing others with great counsel and wisdom. That word was in French since the 1250s, when it was borrowed from the Latin word politia, which meant "civil administration". It's not too much of a semantic stretch to connect that to Ancient Greek polis ("city"), and that's exactly what happened. Polis was a pretty broad word, as it could refer to anything from a people-group to a fortified city-state, and was around in the language for quite a while. If we go back far enough, etymologists reconstruct it to Proto-Hellenic ptolis and Proto-Indo-European tpolh, which could mean "citadel" or "hill". Since its introduction into the English language, usage of the word police has been on the rise, and currently composes 0.0075% of all words used in literature.
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.