"They were the footprints of a gigantic hound!" Those canine tracks in Arthur Conan Doyle's The Hound of the Baskervilles set the great Sherlock Holmes sleuthing on the trail of a murderer. It was a case of art imitating etymology. When Middle English speakers first borrowed sleuth from Old Norse, the term referred to "the track of an animal or person." In Scotland, sleuthhound referred to a bloodhound used to hunt game or track down fugitives from justice. In 19th-century U.S. English, sleuthhound became an epithet for a detective and was soon shortened to sleuth. From there, it was only a short leap to turning sleuth into a verb describing what a sleuth does.