Asteroid is now one of the most widely used words in English. For more than two centuries it has been assumed that the astronomer William Herschel created the word, but that assumption can be shown to be false. This paper reveals for the first time the true identity of the person who coined the word asteroid, and the origins of five other related words: asteroidal, planetoid, planetkin, planetule and cometoid. In the cases of asteroidal and cometoid, this paper corrects errors in the OED.
