Etymology is the study of the history of words and how their form and meaning have changed over time.

For languages with a long written history, etymologists make use of texts in these languages, and texts about the languages, to gather knowledge about how words were used at earlier stages, and when they entered the languages in question. Etymologists also apply the methods of comparative linguistics to reconstruct information about languages that are too old for any direct information to be available. By analyzing related languages with a technique known as the comparative method, linguists can make inferences about their shared parent language and its vocabulary. In this way, word roots have been found which can be traced all the way back to the origin of, for instance, the Indo-European language family…