Yellow. The word used to describe everything from sunshine to jaundice is one of the oldest color words used in the English language. The word has its roots in Proto-Indo-European, a now-defunct language believed to be the ancestor to a smorgasbord of modern tongues, like Afghan, English, Iranian and Greek. However, there’s no written evidence of the language. Etymologists, experts who study word origins, used detective work worthy of Sherlock Holmes to determine the original Proto-Indo-European word was ghelwo. From its ancient origins, the word entered Proto-Germanic, another extinct language for which there are no written records. Etymologists speculate the word for yellow was gelwaz. Proto-Germanic gave birth to even more languages, such as Old English, Middle Dutch and Old High German. It was through Old English, the tongue of the Anglo-Saxons, that experts find evidence the word for yellow had become geolu or geolwe. In fact, the oldest written use of the Anglo-Saxon word is found in the epic poem Beowulf, which was penned in Old English sometime between the 8th and 11th century. The unknown author used it to describe a shield carved from yew wood. So the next time you say the word yellow, consider that you’re using to a word with origins that go back at least a thousand years—and likely much further than that.